I would have to agree, I owned a Harley prior to buying my first CB750 and it still was Very heavy. It's center of gravity is pretty high and high seat height (which I guess can be changed if going cafe). Now don't get me wrong, I absolutely love my 750 it's a 78 K. But If you've never ridden before you may be better off with a bit smaller bike. I've always wanted a 550 too. Keep us posted, this is the best place for info on these older bikes and everyone here is awesome with re-builds and questions.
Best of Luck, You won't be regretting any of them but just be careful at first, that's all... maybe get some engine case crash bars....