Watched this last night with one of my sons. Had read a very positive review in the local rag & being a sucker for stuff with a Time Travel theme, I was in for it. End result, loved it. Ryan Reynolds was superb as the leading man, new comer Walker Scobell was wonderfully effective as his younger self & the rest of the cast, quite well known in the main, carried their roles off very well. The overall concept did not strain my suspension of belief faculties too much at all & very little jarred with me, which being a pedant from way back & hating stuff that just doesn't/couldn't work, can be taken as a recommendation.
Steve.