Well, both have button problems. The H3630 only supports one button press at a time, while the e310 has a button delay. Other than that, both probably are about the same; the e310, though, has a nice advantage since it has an SD card slot built-in (you're going to need extra memeory for any serious gaming, 32 megs just doesn't cut it) while the 3630 needs a bulky CF expansion pack.
Why choose those, though? There are plenty good new PPC's out there that are better than those and are fairly inexpensive. Consider the Dell Axim, for example.