Nailed it... Its all a matter of preference. I love the lore of most chapters, but my hertiage is danish so im more inclined to like the space wolves (VIKINGS!!!) and i just flat out love the Dark Angels story.
Ah, I don't know, really. I guess it's a good lineup of chapters that accurately portray the diversity of the Space Marine chapters as a whole, at least for a first announcing. What I'd be hoping for them to do is to release all chapters, the difference between them being strictly affinity towards a weapon or a small buff (e.g Blood Angels do slightly more damage in melee, Imperial Fists get slightly higher HP, stamina, whatever.) It'd be possible of all successor chapters shared the same small buff as the founding chapter. The main difference would be cosmetical - both colouration and, in cases such as the Space Wolves or Dark Angels, armour design.
Um.. NO! All Space Marines need the same specs... Just like in the lore. Any differences in performance need to be a result of a combination of skill and wargear. I support your desire for numerous Chapters, at least all the first founding and major successors, but for launch I think it would be better if we kept the KISS principle in mind.
Oh crap, I'm starting to sound like a Ultramarine Yeah, all chapters need the same specs but... some special abilities should be reserved.
They aren't the same though. Different combat doctrines lead to focus on different areas of expertise. Their organs are even different.
Same tabletop specs = same specs in any game. Marine for Marine they are the same where it counts. The books allow for some physical trait differences to give character to special characters. But let me be clear... Space Wolves are not stronger than other Space Marines.. The only differences in physical attribute potential are minor things like Radiation resistance and whether or not they can spit acid... Are SW more aggressive? Heck yeah... but not stronger or of better potential...
Blood Angels, for they prefer melee combat above all else, and melee is reserved for the real manly men!