Those are both very good bikes, but I'm gonna keep harping on one negative issue I have with the Enduro until everyone is sick of it...and I hope Spec gets sick of it first. Spec used a proprietary shock desgn on those Enduro models. Their DHX shocks have no schrader valve for the boost chamber tuning, a very important and valuable issue on a DHX shock...air or coil. There are also some length and stroke oddities in the shocks for some of the Enduros, like the 8.75 X 2.5 applications...but it does sound like a few have installed an 8.75 X 2.75 shock on their Enduros...but you still can't access the boost valve pressure without removing the shock.
We sell both Trek and Spec at our shop, and I own 2 older Enduros that I like very much. But Spec ought to have its fingers slammed in the door for choosing this shock setup. I think they could have easily, at their point of manufacture, have installed a 90-degree valve or a hosed remote for the boost chamber, and the length stroke issue could have been resolved with a different shuttle. I was going to do an employee deal on an '05 Enduro and just replace that 5th Air that was on it, but alas, this shock issue killed that idea. The '06 models at least have better shocks, but still that limited tuning issue is present.
If the ability to fine tune your suspension isn't a big issue, then perhaps all of this is a non-issue. Otherwise both very good bikes.