1. Cheap adaptor to convert back to DVI. Big plus.
2. Audio. While useless to gamers, its a big boost to home theatre users and consoles.
3. Long cables, thin plug (DVI was massive!) - i'm running 15M of HDMI cable between rooms. try that with DVI.
#1 It is kind of ironic that DVI was developed for computers and DVI was such a good standard that they used it to create HDMI; however, their roles still remain diverse. The cheap adapters are merely a result of the same underlying standard, really no more. I agree, but is really more a coincidence than an intentional advantage.
#2 Digital audio sounds like crap so I think the only real advantage there is one less cable to mess with.
#3 [rant]DVI is cable of exceeding the maximum length of HDMI because they are generally well shielded by comparison. I mean, before HDMI showed up, DVI cables were thick, high quality beasts that nothing short of a microwave could penetrate. Most DVI cables (especially packaged with monitors) you see now have the same internal wiring as and HDMI cable (cheap, limited/no shielding). HDMI lowered the DVI standards of signal attenuation.[/rant] Since they now use equally crappy cable, they get equally crappy distance.
HDMI plugs are obviously smaller but look at what you are giving up. Instead of pins, they use sliding contacts. Pins were huge up to DVI because the signal degradation with pins is far less than sliding contacts. Pins were, therefore, critical to keeping analog in the DVI standard. If you are going to run 100'+ video cable, most likely you are using analog component video or DVI w/ boosters, not HDMI. HDMI was meant for the home theater, not professional applications. HDMI plugs, therefore, are a step down, not up. Sure, DVI's take longer to install but once those screws are in, there's not a very good chance it is going to come undone. HDMI either pops out or it breaks. Cheap plastics for home theater versus durable, long lasting metal w/ plastic casing for professional use.
I haven't really been keepining a track of different monitor connecting standards, but now that you brought it up I must say I am a bit worried about what the future holds.. First I thought that DP will be the new standard... and could possibly take over hdmi because of no royalty fees.
Royalties are a PITA but manufacturers will go where the money is at. They can't just start selling DisplayPort products because everyone not using Apple will still buy HDMI.
Pre-post EDIT: But UDI didn't support audio transfer...
In computers, audio is routed from a sound card (higher SNR and discreet audio processing) to the speakers (rarely incorporated in the monitor unless it is some cheap monitor for business, buy-by-the-dozen, use.
In home theaters, audio is often handled by a receiver. There's also that nagging issue of audio sounding best through analog systems so professional installations (and I don't mean sub $10,000 USD) still opt for keeping audio analog as much as possible which means they don't want to put in the same cable as video.
Bottomline: UDI would be the best solution for computer video. Whether or not the home entertainment industry picks it up like they did with DVI is up to them.
There are monitors out there right now pushing resolutions beyond 5 megapixel. DisplayPort may make sense for TVs but it doesn't make sense for computers.
That adapter is only single-link DVI. It is unclear whether this Sapphire adapter is dual-link or single link. If it were dual-link, that may justify the price differential.