My review is here. I go into a fair bit of detail on the mechanics as Supergiant was fairly quiet about that before release. So a lot of explanation in addition to personal opinion.
http://rpgsite.net/review/3577-transistor-review
(Dont pay too much attention to the number, it's more an obligation than anything.)
I really liked the skill system. There are numerous ways you can allocate your Functions to create viable builds. As I love tinkering and customizing and trying new things, this really sat well with me. I was slightly disappointed that the game mostly travels along a straight line, and the challenge rooms weren't all that challenging. But that doesn't take away from how fun playing around with Functions can be. Or the great visual presentation values.
As for pace, the game is more methodical than speedy. Especially if you are using many limiters, you can't just fly into a combat zone and hope to succeed easily. Requires some planning and patience, although things can certainly get hectic too. I wouldn't say it's too sluggish or anything.