Koolpc -
I own 1/2/4/bo/bo2, have played the solos on top of mw2/mw3 to give you some reference. Solo player it's a bit odd, there are these side missions which if you do to affect the story line in a positive way and these are fairly dull / bad controls hamper it. The rest of it is well scripted as usual and has a fairly converluted but enjoyable plot. You can't take COD games seriously (stinger on horseback), it's an enjoyable B movie of a plot.
MP is currently not balanced (auto-pistols are OBSCENE - it's getting fixed according to dev twitter) but enjoyable. I don't buy COD games for their MP prowess but for the enjoyment i get and if you enjoyed BO then you'll enjoy this. It would appear that static area denial defences are fairly nerfed compared to BO (bouncing bettys can be dodged with duck/prone easily, claymore 1 shot range is really tiny) and the perks are nicely rounded and include a "best of" from previous cod games. It's fast, frantic, you curse when a respawn wave happens behind you etc.. but it's a decent laugh. I preferred the maps from BO1, there is a real super dud for me (huge city map, designed for ~20 people, you usually get 12) but otherwise there's something in the playlist for everyone.
It's ded servers so lag isn't a huge issue, you can get connected to non-uk servers sometimes (had a few french and one balkan?) but it's rare. I'm positioned around ~40k (so i guess top 10) and have a friend who makes me look like it's my first day playing fps' who's top 5k (top 1-2% or so) and while he gets accused a lot, I don't think hacking is all that common. I am not saying i'm not detecting it, but if they are being subtle about it i don't really care - its not common enough for me to notice I guess is my point.
I hugely dis-approve of the nuketown 2025 drama though, they should bring that back right away.