Now I've heard/read that the various witcher school sets are the best armors in the game for which you can obtain. Currently I've got the following armor:

Hindarsjall Heavy armor +649 Vitality
Tracking Boots +298 vitality
Mahakaman Trousers +339 vitality.

Was wondering whether it would be more beneficial to use one of the school sets and give up the 1286 vitality points. Any thoughts suggestions about this here?

It depends on what you want from your Witcher. If it's only vitality increase that interests you, then the Witcher gear is probably not for you. Each set grants differents stats, but the very best armour in the game is the armour that you have to wait the longest to get: the Wolf School Set. You must also complete the Crow's Perch master armourer quest to be able to get mastercrafted versions of any set. You will find gear that will differ plus or minus as you go through the game, but the Wolf Set will always be on par or above anything you can find.

It probably very much depends on your playstyle and preferences... For me additional vitality points have always been a minor consideration - depending on your level you should have several thousand HP already, a couple more or less shouldn't make that much of a difference?

I've found myself going with witcher armor in every playthrough so far, Feline and Wolf school are my personal favorites, heavy armor (Ursine) has never done it for me, Griffin doesn't agree with my sense of aesthetics ;)
The reason people tend to use the Witcher gear is for the bonuses (attack-power, adrenaline-gain, sign-intensity), and in my book those far outweigh some measly vitality points ;)
But again, it all depends on preferences.
On a sidenote, your armor seems to be heavy-heavy-medium (Tracker's boots)? Might be better to stick to heavy if you have the Bear School techniques enabled...

Ok went with the Ursine heavy armor. Except for the HindarsJall Heavy armor. Due to the fact that I liked the stats a little better. Went with heavy armor due to the fact that I don't use signs all that much. Only use Axii when required and and sometimes aard. Mainly use Igni.

Sure, sounds good. I like the looks of the Ursine armor set, but as stated above, heavy armor isn't really for me.
Yes, if you don't use signs much that does make sense.
I like the attack bonus on the Feline armor, if you add the Cat School techniques to that and maybe invest a little in fast attacks you end up dealing quite a lot of damage (and god forbid you throw some greater red mutagens in there, too). Combine that with quick stamina regeneration and quen, and (if you're not incredibly bad at dodging) you become pretty much an unstoppable killing machine.

Since money really isn't an issue in the second half of the game, I usually craft all of the Witcher armor, just for fun, and to mix it up a little sometimes.

The best armor I've sound so far was the Viper School gear
http://www.gosunoob.com/witcher-3/viper-armor-witcher-gear/

You need to have Hearts of Stone for this one though.

Was checking out the stats and will have to admit that I like them. I've got the Hearts of Stone just haven't gotten into the main part of it as of yet so I've not gotten the quest for it. Guess I'll have to do a respec when I get that set as currently I'm running with heavy.

I still need the horse gear and the decorated Saber for the Ofieri gear so that I can get that Achievement but yet to find that. Heard that it's glitched.

The horse gear should be available via the Ofieri merchant (gotta race him for the saddle). There was a bug there, but it should have been fixed with 1.11 (it was for me, anyway). As far as the sabre goes, IIRC I never even bought the "official" Saber from the merchant, just used one of the generic ones I picked off some random NPC, the achievement unlocked anyway.

One thing you should know: If you want to have the viper gear, the sword (I don't remember if it is the steel or silver one) is only available when you pick the "right" dialogue option at the end and then all you have to do is find the sword although time is rather short.

Yes there are two different sets, once is available early on in White Orchard and the other was added in Hearts of Stone.

Thanks for the information as I'm just getting ready to start the main quest for Hearts of stone. Someone told me that there was an auction for one of them I hope that 20k in crowns is enough.

It's plenty for the auction, you won't need nearly as much.

Thanks for the info now to go take down a frog prince.

Actually, as far as I can remember, none of the witcher gear is purchased during the auction.