My wife and I saw this the other day. Since my wife is Japanese, she just sat back and enjoyed it, while I was struggling to read every subtitle and title card of the characters lol.
All in all, we both enjoyed it, it was an entertaining movie with amazing action and humor. I think my wife appreciated the humor more than I did since she understands the bureaucracy of her county more than I do, but I got a kick out of it too.
Overall, it had a very good story and characters, I didn't find myself bored at all, but I did find Satomi Ishihara's character quiet annoying and felt the movie would've been better without her. Or even get an actual American actress instead because her English accent was horrible.
When my wife saw pictures of Shin Godzilla, she hated it!
But when she actually saw it on screen she really liked it and felt the design went well with the theme and story of the movie. I liked it too actually, I thought his evolution was quiet good, although I did wish he had a 5th stage resembling more of the classic Godzilla. But oh well. His beams we really amazing, I was most impressed by this than anything else. When his spines lit up and the fire, smoke, radiation emanated from his mouth, I was like, "Oh yeah I know what's coming next!!" Exactly how I felt when Godzilla 2014's tail started lighting up!
I did find the ending a little unsatisfying. I understand that they don't want to kill him off so they'll be opening for a sequel, so I think it would've been better if he remained unstoppable. After all, you can't stop a tornado or a hurricane, you just have to wait until it goes away and better prepare for it's return.
If Toho wants to continue with more live action movies, my preference would not be a Shin Godzilla 2, but going back to the classic Toho Godzilla. I really can't see other Toho kaiju showing up in the Shin Universe, they just don't fit in unless they completely redesign their look and origins. So my hope is that Shin Godzilla is just a one shot.
It was also fun being in a theater with other Godzilla fans with their Godzilla t-shorts and toys. Nothing tops our experience with Godzilla 2014, but this was the next best thing!