Ignoring the bickering in this thread between everyone, here's my honest input so far:
I have played and owned every CoD online since CoD4, except Bo3. I played the Bo3 beta when it came out, and it didn't do much for me, so I didn't buy it.
That being said, this is my first CoD in 2 years, so I may have a little less CoD fatigue than the average person here, seeing as most people on this forum probably bought and played a lot of Bo3.
I'm also not going to lie, I still wasn't super excited for infinite warfare, I was excited for MWR, that was my main intent behind the purchase.
I will be blunt... I don't hate IW, but I am also not in love with it either. I do however, enjoy playing it... I just happen to find myself playing MWR more often. There's certainly more content for IW, but I play and enjoy MWR more seeing as those were my highschool/college days, and this is a way of reliving that for myself.
The balance is decent in IW, I feel like I can use every weapon in every class, and be able to compete within some margin. Even the weapon variants don't add that much of an advantage as AW weapon variants did.
Simply put, its a good game, but if you're someone who started the franchise playing Cod1-4, then you may find yourself spending more time in MWR. I don't mind wall running and all that, it's a nice change, and I'm not going to be one of the ones complaining about futuristic stuff.
They have accomplished part of my desire of remastering Cod4, now I'm just waiting on Mw2. After that, I would prefer they just scrap all of CoD and come up with something new. I've been playing CoD for 10+ years, and I've been fatigued by the series since after MW3. I've just been buying out of habit.
Work and the girlfriend take up most of my time. When I do have time to play games, IW and especially MWR are good things to blow some relaxing time on.
TL;DR - Don't be cheap. Buy it. You hate it? Sell it. You only wasted at most $20-30. Most decent jobs you can start off making that an hour.