Best friend has the DCF899 with pin, it's an absolute beast. I haven't gotten it yet (that pricetag!), but I did get the DCF887B for putting together some serious storage in our garage -- I picked up a 1/4" hex to 3/8" square adapter from Milwaukee and some 3/8" impact sockets, and it'll take wheels off of my car without much fuss. I wanted to get the 3/8" impact as well, but for the pricetag, the adapter seems to be just fine.
I definitely feel that the high-torque is a large tool -- but when you need the extra "oomph", you'll be glad to have it. We had an axle nut on his girlfriend's TL that wouldn't come off with a 4 foot breaker bar, the impact didn't blink at it.