I enjoyed the 18TM in my revo. With the right pipe (Fantom works in mine) and a little shoehorning to install an 1/8 scale clutch, then the 18TM really shines. With the stock pipe and stock clutch, I was pulling wheelies all the time with stock gearing. With the 1/8 clutch and better pipe, I had to up the bell a tooth and drop the spur a couple just to keep the front end down.
Tuned easy as well. I ran a pullstart (hate e-starts) and it would start on the 3rd pull almost every time. Ran between 215-240 pretty much all the time all summer long.
I probably ran about 3-4 gallons through it and it still ran strong. I never replaced a diff or had the trans apart.
Now it's in a baggy all saturated with ARO... my wife bought me a BB kit for Christmas... Then I got a 3.3 chassis and P3 suspension... I haven't run it much yet since it's been so cold, but the few times I have, it made me realize I'm a BigBlock man. As good as some SB's are, BB's just have the torque and sound I like.