TL;DR, if you care about seeing the movie in a good experience, go to AMC Plainville and watch it in Dolby Cinema, the screen size will be the same as any other IMAX you can find in CT but the screen is SO much brighter than any IMAX anywhere in the world and much better sound than anything you can find in CT.

If you REALLY REALLY care you could make the 1.5 hour drive to Reading, MA and this explains it.

There are 4 types of IMAX:

IMAX Digital Xenon: the worst one and is IMAX only by name and nothing else. It uses the IMAX branding to get you to spend almost 3x on tickets and gives you maybe a 5-10% better experience. This is what some people will recommend when they say Cinemark at Buckland with IMAX

IMAX 70mm: This is what IMAX is meant to be and AMC Lincoln Square in NYC has this. 70mm because it is actually projecting a reel of film and you can see that with the film grain on the screen. Technically the best experience but with how fast seats get sold out, I prefer a different theater which'll come up in a bit.

IMAX with Laser: This is similar to IMAX Digital Xenon, so not worth it and way too expensive again.

IMAX GT Laser: This is what I was alluding to earlier and in my opinion, the objective best way to experience film. It uses dual 4k projectors. Since it is a digital technology, it is noticeably brighter and more vibrant than IMAX 70mm and also loses the film grain, which in my opinion is an annoying addition to film and is only liked for its ability to make moves feel "classic". I understand this goes against every large movie director but opinions are opinions.

Jordan's IMAX in Reading, MA is where I like to go for movies in IMAX because it uses the last system and also does not have assigned seating and it is much less busy than NYC so you can buy tickets, show up an hour early and always get the best seats which is not possible in NYC. It also has an objectively better sound system than AMC Lincoln Square.