Faster is always better, but honestly I wouldn't stress about it too much- for power consumption reasons it's probably best not to shut down and restart all the time, and overall deblet seems to be stable enough that frequent reboots shouldn't be required either.
If I had more free time (and skill), I'd be spending it working on power conservation, gps and DUN support, and maybe speed optimizations for specific apps (a faster browser would be nice, and there's been some chatter about media players and such). Bluetooth DUN and maemo-mapper (well, and a key/screen lock) are the two things that keep me from running deblet full time at this point; if we could get those 'killer apps' to work then people wouldn't really need to boot back and forth.