I personally came to rails after having been an active rubyist for a while, and I think it really gave me some perspective on some of the hype. Frankly, my opinion is the whenever you are looking at frameworks and systems like this, try and match it to yourself as much as possible - if you are already a PHP kinda guy, and you like it, and you have stuff set up in it, then stick with it; it never hurts to play around with stuff though.

And make sure not to get caught up in the confusion many web minded developers seem to get caught in: rails != ruby. This is an extremely important point. Seriously, hanging out in #ruby-lang listening to people whine about ActiveRecord is annoying ;D