Kazaa-
Couple of things to look out for here... I made the transition a few weeks back after much deliberation and research, trying to figure out the best way to go. As with everything else in life, there's always trade-offs.
I was running on a single 24" Sun monitor @ extremely high res which was perfectly fine, but the lure of the triple monitor panoramic view kept niggling at me, so I finally went for it.
Some things to consider:
probably most important, widescreen monitors side by side, especially three 24s are going to squash your view disproportionately like you are looking through a huge slot, like out of a bunker. Some people have no problem with this, others will be very unhappy with the resultant unnatural F.O.V. . I knew immediatly I would hate that kind of result, so I only considered monitors that could rotate to portrait view. This little tidbit of info saved me from making a very expensive mistake.
I tried it in landscape and portrait mode and IMO for a flying sim, having the "normal" field of view using portrait mode makes a big difference - for racing sims, maybe landscape mode would be better, I only use it for AH but at least there is the option to switch to landscape-widescreen if you want.
From all my research, spending all that money for the Matrox hardware is just dumb. The Eyefinity solution appears to be the latest and greatest, but as some have said still relatively new and possibly buggy. I settled for SoftTH (Triple Head to go) for free and although a little hinky to set up at first, (you gotta do the research an read up on the forums) it has been working perfectly once I figured out how to set the resolutions and game settings.
The last general point I will make was probably the hardest to accept. Your frame rate will take a huge hit. Its really very simple and obvious ( although its something I neglected to consider) whatever your FR was with a single monitor, divide it by three and that what you will end up with. I was enjoying 180 - 200 + frame rates before and now it hovers around 60, dropping to 50's in furballs. not terrible, but a significant concession nonetheless.
Is it worth it??
yes - its very cool
yes - having those side screens does make a huge difference in immersion and visualization
yes - your wife/GF will think you're an idiot
yes - it does improve your SA, but not your ACM
negatives:
Those screen bezels - initially they bugged the watermelon outta me, but they eventually are less and less noticable.
3 screens take up a lot of desk space, you're gonna need more room!
you gotta do the research and your homework and will probably need to upgrade
something along the way.
Im sure there are many other points I forgot to mention, but those are the ones I thought might help you along. G'luck and btw, no I don't think I could go back to a single monitor.

p.s. there are triple monitor setups available without the bezels, but they are crazy-expensive. you can check them out online, multimonitor.com or something ...very cool but way overprced.
TC