Personally just 2 Perks are truly mandatory for me: Hardline and Scavenger. I also like Engineer a lot but I cant use it all the time (due to Equipement use).
Flat Jacket: its very useful BUT I really prefer using a Trophy System. It has so much advantages when compared to Flat Jacket: it "eats" the explosives protecting you 100% (not 60%); it gives you Score (which Flat Jacket doesnt give) and it also helps your team (while Flat Jacket doesnt). So I just stopped using Flat Jacket!
Blind Eye: I used it a bit in the beginning but didnt see on it a big advantage. Stealth choppers are difficult to avoid (thats true) but if we are talking about a DragonFire an EMP grenade can easily destroy it (and I always have one of those with me )
Cold Blooded: I used this Perk religiously in the first weeks. I thought it gave me the advantage that Assassin gave us on MW3: not having our name written on Red letters, and to be able to avoid Target Finders. BUT then I saw the usual CoD mess: sometimes the Perks arent really functioning, and this is true. I started seeing people using for exemple other Perks on Perk 2 (not Cold-Blooded) and they were totally dark and invisible like they were using Cold-Blooded (which they werent, I saw on Killcams). I waas also still picked by Target Finders a lot of times. So I gave up on it and just run Scavenger on Perk 2 now. Not much of a difference to be honest!
Definately Cold blooded (damn target finders) often I have to give up toughness for it though
Also engineer to avoid and EMP/Hack that annoying danger close+bouncing betty+shock charge combo
Perk usefulness is very much reliant on what the enemy has in their locker. Some examples -
You use ghost, but the enemy dont have UAV in their set up, you wasted a perk.
You use flak jacket, but the enemy dont use explosives against you, you wasted a perk.
You use Engineer but the enemy dont plant any equipment, you wasted a perk.
You use cold blooded, the enemy dont use target sights, you wasted a perk.
You use tactical mask, but the enemy dont throw any tactical grenades, you wasted a perk.
Of course it is vice versa, if you use these perks and the enemy does use these attacks then you win big time. It all boils down to a couple of things. First is luck, what the enemy does aganst you. Second is your own skill in setting up classes and being able to switch to the necessary and most useful class at the earliest opportunity in the match. Have the right class for the right stuation and you sing the praises of the perks; assuming you also have the awareness to realise that you would have died a lot more had you not had the perks you had. Have the wrong class for the situation and you will be on here saying how useless the perk is; failing to realise what you did wrong.
Pro perks were just an overcomplication, a grind which stopped people prestiging and gave those with pro perks an advantage other those who didn't. Atleast now everyone is on a level playing field in relation to perks.
Most of the pro perks only served secondary purposes though. There is no such thing as a "level" playing field due to the assortment of perks in all of the CoDs. The only "level" playing field is taking out perks from CoD all together, but I do not support that idea though.
It is a level playing field, everyone has the same perks rather than a perk and than that perk having a secondary function (which is sometimes better than its primary function MW3 sitrep pro for example), it's up to us to decide which perks are best for us and what situations they work best in.
To a point it's a level playing field now, but you still have people on lower levels who don't have everything unlocked, or people without certain attachments unlocked for their weapons. In older CoDs anyone could have any perk regardless of their level, but then it took time & often effort to unlock the "pro" version.
That was the great thing about COD points, you could unlock the attachments you wanted whenever you wanted them. Anyway personally I feel having no pro perks has helped perk balance alot.
I agree, and also that having to "earn" the pro perks prevented a lot of people from prestiging. My main account is still level 55/prestige 1 on BO1 because I just didn't want to go through the effort of re-earning Tac Mask & Flak Jacket pro again.
I actually kind of miss the CoD points, but I see why they went with the system they did in BO2. First off, having to advance in ranks before you can unlock certain items forces you to experiment a bit more with other things, plus of course the way the system is set up you cannot unlock everything unless you get to Prestige Master. That, plus the permanent unlock tokens and the fact that your challenges don't reset when you prestige, is making far more players prestige. And that tends to keep the playing field relatively level, at least through the first couple months of the game's life (or would, were it not for the prestige glitches).