Does the new Mega file-sharing service live up to the mega challenge?

New Zealand entrepreneur Kim Dotcom still wanted by U.S. authorities on allegations of copyright infringement launched a new online service this week for storing and sharing files.

Staying true to his outsized personality and reputation for excess, Dotcom unveiled the Mega service with great fanfare, renting a helicopter and hiring actors dressed as police agents to re-enact a raid that followed the shutdown of his first venture, Megaupload.

The new Mega service promises user privacy and a generous 50 gigabytes of free storage space officially for documents and other files you own or are authorized to share.

What Mega doesn't promise is a good experience. Instead, it feels like a work in progress.

Several other services do what Mega does and do it better. I have reviewed Dropbox, Google Drive and Microsoft's SkyDrive, and I like the way they let people store files remotely using a Web browser. Like Mega, they all let you create links that you can send to friends to download and view specific files.

All three go further by letting you do so from a wide range of browsers. Mega warns that using anything other than Google's Chrome browser is bound to cause problems. That includes Microsoft's Internet Explorer, which comes with every Windows computer, and Apple's Safari, which comes with Mac machines. Chrome comes with, well, Chromebook machines, which few people have. Mega says it's pushing the envelope with technology that other browsers lack, and it offers links when using other browsers to download and install Chrome.

Mega also doesn't have one of the best features available with Dropbox, Google Drive and SkyDrive - the ability to create a special folder on your computer that automatically syncs with the service. You can add a document to your Dropbox folder on your work computer, for instance, and it will automatically appear on your Dropbox account online. When you're home, the updated document is waiting on your computer. Make a change there, and the work computer will get it, too. Mega says it's working on something similar.

Same goes for mobile apps. Mega says apps to access files on smartphones and tablet computers are coming.

Mega also isn't as versatile when it comes to sharing options.

Dropbox, Google Drive and SkyDrive offer two main ways to share individual files and entire folders. You can create a Web link that anyone can use to access a file or folder without signing up for an account. You can also add specific users to a permission list and invite non-users to join. Shared files and folders would show up in their accounts, without needing a specific link. Either way, you can revoke access to specific users or cancel a link entirely should you change your mind.

With Mega, files can be shared only through a link, but there doesn't seem to be a way to cancel it. With Google Drive and SkyDrive, you can also give others permission to edit documents with the link. Links with Mega and Dropbox are for viewing only.

For folders, you need to add people's email addresses to the permission list, and those who are not already users will get an invite to join. With this approach, you can choose whether to let them read files only or make changes. You can also revoke permission. But again, this works only with folders. To allow someone to edit one file, you have to put it alone in a folder and give that person permission to edit that folder.

Dropbox, Google Drive and SkyDrive let you share both files and folders with either method.

One thing Mega has that other services don't enhanced encryption of files. Unless you're sharing a file with someone, Mega says, you are the only one with a key to view that file. Mega says its employees can't access it, even under the threat of legal action.

Mega also offers far more free storage than any of the other three services - 50 GB compared with 2 GB on Dropbox, 5 GB on Google Drive and 7 GB on SkyDrive. Upgrade plans on Mega start at 120 euros ($160) a year for 500 GB. You'd have to pay $499 to get that on Dropbox and $240 to get just 405 GB on Google Drive. SkyDrive doesn't even offer that much. Unlike Google Drive and SkyDrive, Mega doesn't impose any limits on the size of any one file.

All that space is perfect for super-large files - say, a feature-length movie. Of course, I don't condone piracy, and Mega says it doesn't, either. Its terms of service prohibit you from using Mega for copyright infringement. If you do, according to Mega, it's you who will be liable, not Mega. Mega says it will remove links to unauthorized files brought to its attention.

That was Dotcom's position, too, when he presided over the now-shuttered Megaupload service. It had been one of the most popular sites on the Internet until last January, when U.S. prosecutors shut it down and accused him and several company officials of facilitating millions of illegal downloads. U.S. authorities are trying to extradite Dotcom from New Zealand, where he is free on bail. Mega's launch Sunday came on the one-year anniversary of the arrest of Dotcom and the raid on his home.

What makes Mega different from Megaupload is encryption. Mega says it can't see what's in the files being shared, and thus it cannot be held liable.

In addition, Megaupload deactivated files on free accounts unless someone downloaded that file at least once every 90 days. According to the government's indictment of Dotcom and related parties, that made Megaupload useless for long-term personal storage of legitimate files, as only pirated materials with frequent downloads tended to avoid deactivation. Mega doesn't appear to have a similar expiration, though the company didn't respond to email requests to clarify that and several other points.

One thing is similar Like Megaupload, Mega allows you to upload files without an account. That means you don't have to share your email with Mega, though it's possible the service will have your computer's numeric Internet Protocol address if you're not using an IP-masking service like Tor for anonymity. If you upload a file this way, you can create a link that you can give to others to download your file. This is something not available with Dropbox, Google Drive and SkyDrive.

Still, that's not enough to overcome Mega's shortcomings. Mega's sharing options aren't as versatile. The service doesn't even let you change a compromised password or reset one you've forgotten. Once again, Mega says that's coming. I also had trouble signing up with Hotmail accounts. Emails that Mega sent to verify accounts didn't go through. I even checked the spam folder.

Mega is useful for sharing large files that won't fit on a free Dropbox, Google Drive or SkyDrive account. That can be one that exceeds Google's 10 GB limit or SkyDrive's 2 GB cap for a single file, or that can involve several that collectively exceed your free space. (Google's single-file limit, by the way, is already double what you get for free.)

For routine use, Dropbox, Google Drive and SkyDrive are all more versatile and easier to use.