For the guys that have used both widths, What real gain is there. I've got to replace mine and woundering if it is worth the expense to rig up the suspension?

I switched mid season last year and didn't notice much difference in et. But I only run 1/8 mile. Guys are seeing almost 3/10 in quarter mile testing. You will need to re-clutch as you are spinning 25lbs less rubber.
The BIGGEST difference is the sled goes absolutly straight every time and my 60 fts are a little better.

The 10.5 is only $50 more and I would buy it.