BTDT on the whole round vs. lo-pro battle - and lo-pro won out. I have a round reel on my heavy salmon/sturg outfit. I don't cast that a whole lot, and when I do, it uses a lot of weight so not an issue. With the lighter steelhead/bassin setups - the low pro is the way to go. Much easier to cast lighter baits/lures, easier on the hand with lots of fishing. My favorite reel has become my Revo SL (that's the Revo S, left hand crank model). It casts like a dream, it's light weight, and it's just awesome.
I'm a big Shimano fan, but for my low pro bait caster reels, I'm pretty stuck on my Revo. I plan on getting another, for my currently reel-less bait caster.