One thing i was worried about was "reduced" performance.
I bought my new computer cause i wanted to have RACE07 to run in all its splender and didn't want to have that ruined.
SoftTH hasn't had me lowered my settings one bit in RACE07, GTR2 or rFactor. I max out the graphic on my 8800GTS / Intel6850 and 4 GB ram setup. I have yet to discover any worse performance. If i should run some fps counter i would probably see a decline, but thats nothing i experience while racing. Soo, please take the "worse performance" with a grain of salt. It will tax your system. But its not neccessarily very bad.
Good thing you can do to improve performance is running the side monitors in a lower resolutions. People are running as low as 640x480. (Not me). And people is also running the side monitors on a different color depth (16bit).
The only downside i see with softth:
a) It crashed rfactor everytime when i alt-tab out.

b) You must have the knowledge and room to fit another PCI-e. Preferable in a x16 slot (i have).
Matrox is also much better in software support.
And look at the official supported games and ask your self in what games do i want to use it. If you are a FSX addict, move along, get a matrox. If you are a carsimfreak. GTR2, rFactor, RACE, LFS and also reports of iRacing is supported with this.
As my left screen i have a discarded tft monitor from work. Half the screen works, the rest is ... totally rubbish. But when you drive you focus on the center screen and notice stuff in the left and right monitor. (i.e why people don't mind fiddling with resolutions on the side monitors)
I know i can't transfer your money to my world. But in my world a XBOX game cost $100 ~ 550-600 SEK.
A 8600 cost $100 ~550-600 SEK. Cheaper cards is by merarly 100-200 SEK so it was a no brainer for me.
Having a triplehead setup adds so much to the imerssion of the game that i couldn't believe. And sine the only cost was 1/6th of the price of a Matrox box i just had to try it. Are you tech savvie, you have room and you don't mind spending the weekly lunch money on a new graphic card. This is certainly worth trying.
Oh i forgot, the biggest downside (really) was that i really wanted to race Talladega. Just to be able to see the views!
Today i will go gett me a 22" monitor as the center. This *is* my gaming configuration for times to come!

Ps.
If i don't get married because of this? Who cares!