I thoroughly enjoyed this flick! It does start off a bit sluggish but once it hits its stride it is a very fun romp all the way to the end with a more personal, smaller scale story.
The shrinking/microverse environments looked fantastic, the ants looked great and the vfx for the young Michael Douglas was shockingly photo-real. The shrinking elements provided a fresh breath of air to all the action scenes and there were some truly unique ideas ranging from Ant-Man and Yellowjacket fighting inside a briefcase to the entertaining finale in Scott's daughter's room with shrinking/enlarging hijinx galore, (Thomas Tank Engine!). Another great sequence was the trip through the Quantum realm. It literally was trippy

and something we haven't seen before. That's the type of crazy, psychedelic imagery I hope we see in Dr. Strange.
Scott's motley crew of burglars walk a tight rope of being either funny or annoying but luckily it never felt like the action and drama were undercut due to their involvement. I was especially worried about Pena but he actually shined in all his scenes.
Darren Cross won't make any top ten lists for villains, he's kind of a poor man's Obidiah Stane complete with bald head but he fits in with the student/mentor relationships explored in the film. If I was going to reach you could say he's similar to Ultron in the comics in that he both loves and hates Hank for taking him under his wing and then abandoning him. Also much like Stane, he sports a badass suit. I said it before and I'll say it again, love the Yellowjacket design.
Marvel's casting continues to be stellar with Rudd, Douglas and Lily. All of them turn in good performances and each of them had issues and traits one could identify with. Their chemistry was great and by the end they felt like a tight family. I mentioned the young Michael Douglas already but it should be stated again, the de-aging fx were superb. It'll be interesting to find out how they accomplished the effect but if I had to guess, I imagine it was something similar to how they achieved the older Peggy Carter in TWS only reversed. (And if you're like me and interested in reading how the vfx were accomplished,
FXGuide.com has a great article on how they achieved the young Douglas as well as many of the film's other effects.)
Falcon's guest appearance was a fun one. It's just too bad Marvel chose to spoil it in the commercials.
Evangeline Lily is perfectly set up to become the (2nd) Wasp by the end of the film but I loved that a backstory for Janet was explored and shown briefly. The film also sets up the possibility of her return with Scott's escape from the Quantum realm planting the seeds in Hank's mind that she could still be alive and rescued.
Considering this film's loooong development history and sudden directorial change so close to production it's very surprising and allaying that it turned out as well as it did. Personally I never understood the adulation for Edgar Wright based on his previous films but you could also say the same for Peyton Reed and he turned in a solid effort. I'm sure there will now always be a debate of what Edgar's version might have been for better or worse but I feel we got a pretty damn good Ant-Man film in the end.
Go see it, spread the word! I saw it in 3D and thought it looked great, this is probably one of the few films that is perfect for a 3D experience. Looking forward to seeing it again!
Regarding the 2nd credit scene:
I'm not sure what was going on in the scene exactly. Cap and Falcon have Bucky (visibly beaten with his metal arm seemingly restrained in some sort of vice). Did Cap restrain him or did he find him like that? Whatever's happening they need Ant-Man's help and they don't want Stark involved.