Just finished up my first playthrough, right at 9 hours in the in-game counter on normal. Found 36/50 collectables, most of the missing ones are in Act 1.
Bravo to The Coalition! I was really worried for the future of Gears (especially campaigns) post Epic given I've been underwhelmed with Halo campaigns post Bungie, but they really nailed it IMO.
Campaign was 100% worthy of the series, with lots of great encounters and set pieces. I liked the new characters and enemies as well, and it did a great job of setting up the series going forward.
Super impressed with how good the PC port runs as well, probably the best looking and performing game I've played to date. Looking forward to checking out Horde later after getting some work done. I've never been big on Gears Vs MP, but I'll check that out as well--though probably tomorrow and beyond in hopes the standard release bumps PC player population.