My local California waters are 48F-54F year-round, air temp 50s winter, 70s and rare low 80s in summer. My first suit was the Aqualun Solafx 8mm/7mm semidry, very similar to the BARE in the post above. It worked well for awhile, but I eventually went for a drysuit. On of my occasional dive buddies dives a Deep6 7mm here (w/ separate hood), and he's happy enough, but personally I think he might go for a drysuit eventually if he starts diving more frequently.
So I think both suits are reasonable in temps in the 50s, long dives in the 40s are pushing it unless you're a superhero. I have no idea if they would be useable in FL winters since I've never been there, but if you ever see people there with a 7mm or 8mm, then it'd probably be OK.
By the way regarding price difference vs Aqualung or BARE semidry, the D6 7mm is a $400 suit. But Deep6 couldn't sell them fast enough so decided to discontinue them, and cut the price down to $225 to clear out inventory. So it's right up in there with the 8mm semidry's in terms of price.
I have a Deep6 3mm and have used it in Bonaire, water temps 77F or so. It kicked ass, I was really happy with it. So happy that I almost bought the 7mm as well. But since I already have a 3mm, an 8mm, and a drysuit, I don't really *need* the 7mm, ended up not splurging for it. I still think about it sometimes, though...