I got the exact same result after clearing the nekker cave many times with an old and new character.

I thought I was the only one. I'm like 2/3rds done with Act I on my latest play-through and I only have 2 greater mutagens o_O

Weirdly enough, I think this is true.

I also support this. In an ongoing game I received 1 lesser mutegen after about 50 monster kills. This was 1.1 game patched to 1.2. In a new game started after patch 1.2 I received 1 greater, 3 lesser in killing about 40 nekkers. This was about the same rate as my previous game before the patch. Since these ARE random numbers it might just be due to luck but the impression is there at least.

Well I started a completely new game with the 1.2 patch. And the situation got this way. Yea, some low level mutagens, five medium level mutagens and a couple great, of them only one greater strength mutagen and no greater critical mutagens. I usually fill all my mutagens slots with greater critical mutagens and a couple of greater strength mutagens (for carrying capacity and armor improvement "+2"). It really helps with my swordsman career. I usually make a witcher 3-4 second level abilities, one way up of swordsman abilities, all the important ones maximized and the few filler ones with only one point and whatever is left in signs (magic). So this situation when I have killed everything there is to kill and about to choose either iorveth or roches' path and got almost no mutagens is really disapointing. It's not that I really "need" them as someone expressed himself here. It's just that I like the criticals animations and effects. And who I'm kidding, I love those instant kills and such : ) : ). This change is crippling the game for me. Not for fighting difficulty, I love the role playing of a powerful witcher with interesting special superhuman abilities. Although it's strange that for some it's the other way around. Well, it's true the first playthrough was done mostly on easy and now I'm going normal/hard. So that may have some to do with it. I will try to switch to easy and see if there is a difference. If so I will have to go mutagen hunting on easy, and never use hard for such things. I'ts kind of stupid. You should get MORE mutagens for playing at a harder level and killing more difficult enemies. Well, we will see if my guess is correct, or if the developers simply went to far fixing a thing that didn't need fixing. : ) : ).

Just as an added scientific inquiry :) I did start over post patch and my results are similar to yours. I suppose I just needed to start over. FYI one lesser every 25 -ish nekkers now.

Thanks for the reminder...
I am well aware of this mod, I was saying this is something I would like to have seen in the official game per say.

From your post it seems that you still found greater ones just not of the type you wanted. that happened even in 1.0 and is just bad luck. The issue was mutegens of any type not being found.

Well, I'm about to take Triss for a bath, lvl 13, Insane diff (drops should be even more rare as per difficulty description) and so far I got exactly 08 Greater Mutagens, 3 of which are Greater Crits, a couple of Greater Power, same for Greater Vita, one of each Greater Strength and one Greater Enhancement, plus a shitload of lesser and normal ones!

I'm pretty confident that I'll find another 2 Greater Crits, at least, in Act 2. =)

If you live that long (snickers) :)

I found 2 (TWO) greater ones. That's practicaly zero for all intents and purposes. The chance that the ones I have are the ones I need is very low. In this case, yes I got 2 greater mutagens, but for all intents and purposes only 1 usable, because the vitality mutagen is useless for me.
Exactly. On my last playthrough mutagens were more abundant but not too much either. I had like 3 or 4 greater critical mutagens, a couple of greater strength mutagens, five greater vitality mutagens and so on. It was a very suitable number to select from to use for improving my character abilities slots. With the 1.2 patch there is almost nothing to chose from if you don't want to put in lower quality mutagens (after all they aren't removable later to put in a better one).