I'm learning Ruby while learning Rails also. I didn't find the Ruby syntax very confusing, but the humps for me are "How do I make sure I'm doing this the right way even though I'm a n00b? How do I get over being a database control freak and give in to db management using ActiveRecord?"
I came from using CodeIgniter, which is a Rails-esque framework for PHP. Fortunately, the "opinonated" structure etc. made a whole lot of sense to me, and in retrospect makes me wonder why I didn't jump into Rails sooner.
As far as DB management, I don't buy the whole Rails kool-aid as far as DB constraints go. I still develop constraints, set up foreign keys, and hack around AR when it's expedient to do so. AR is marvelous at solving 90% of the standard boring CRUD without any headache, but it isn't a silver bullet, and you can still shoot yourself in the face performance-wise with it. Don't be afraid to overstep its bounds when necessary, but don't prematurely optimize, either.
I've worked in CakePHP since learning Rails, and I have to say that more than anything, it makes me really dislike PHP as a language. The framework is pretty decent, but Ruby is so flexible and malleable that it really makes working in PHP painful.
I came from using CodeIgniter, which is a Rails-esque framework for PHP. Fortunately, the "opinonated" structure etc. made a whole lot of sense to me, and in retrospect makes me wonder why I didn't jump into Rails sooner.