I would. Some say it doesn't make a difference, but I dissagree. Since I've started rehydrating I've seen a significant reduction in lag time. Anything you can do to make your yeasties happy is well worth it.
I always have. I've only got about 6 batches under my belt and havent' risked not hydrating my yeast. I guess whatever works for you the first time, you will probably stick to. I'm sure there will be other opinions though. I have sprinkled dry yeast on the top of wine must many times without problems though.
Cell wall heath is the reason not just lag time. Hydrating the cell walls with water makes for stronger, healthier yeast. When it has to hydrate in sugar water (wort) it must work harder to get fully hydrated.
I've done 4 batches - 1 liquid, 2 with re-hydrating, and 1 pitched dry on top. The only one to have fermentation problems (due to stalling, perhaps due to colder storage temps) was the one I pitched dry. It went like heck for two days, then apparently stopped in its tracks.
When you consider the fact that re-hydrating takes only about 15 minutes, and you can do that when the wort temp is near pitching temp, and it takes only a minute of effort or so to re-hydrate, it's really a no-brainer for me. I will always re-hydrate from now on. Compared to the amount of time everything else takes, this part is gravy, and why risk the quality of a batch that you've worked so hard on?