Having had both crank (Quarq) and pedal (Garmin Rally) power meters, I think I prefer pedal-based. They are theoretically more portable than crank-based, but I mostly have a preference because you don't have to care about vagaries of bottom bracket compatibility, etc (I sold my last one when I sold the bike due to compatibility issues). I also have SPD-SL pedals, so not something esoteric that it's hard to find compatible PM pedals for. They were expensive (I got the dual-sided version), but aside from changing batteries every 6 months to a year or something, it's been set-and-forget; they seem to just work. To be fair, the crank-based PM I had was similar in reliability and battery longevity, so both were pretty good, honestly. But as people pointed out, yeah, avoid the Shimano crank-based PM's, and do some reading on dcrainmaker.com, as he's got extensive reviews of basically everything.