Originally Posted by khuon
I don't have one for my RB but I do have one for my MTB. I normally have my seatpost set up for XC work on my MTB and this gets me by on most terrain. However, if I encounter really technical stuff, I'll drop the seatpost to give me more room to move the bike around.
Same here... I have marked my XC seat post level on my MTB so I can easily return it to the right spot, but do prefer to drop an inch or so when riding technical spots. On my roadie and commuter, it's an allen bolt - I never need to adjust those.
QR on the front wheel is also essential for me for putting the bikes on the roof rack carriers. You can roof rack carriers that clamp on to the downtube, but I'm not particularly keen on doing that on my aluminum MTB or my wife's roadie. If I ever have to lock the bike up, it's a very fast task to remove the front wheel and lock it to the frame.
Suspension seat posts, particularly cheap elastomer ones (which is what would be spec'd on a $500 bike), are IMHO junk. Go for a sprung Brooks saddle instead if you really need it.