Spin sensitivity of T05 & T05FX

Those comments are probably mostly written by people who aren't really good enough to manage 05 in general, and it's not so much a fault of the rubber. Spin sensitivity really just means a player is not good enough to control a rubber, not that the rubber is going to start acting up and doing unexpected things. Less "spin sensitivity" should also imply less spin able to be generated.

If you can handle 05FX you should be fine with 05.

If you have two same top sheets with a softer and a harder sponge (like t05 and t05fx) you will always see that the harder sponge has less catapult, more speed potential, more spin potential but on the other hand will be less easy to use and more spin sensitive

I've been using Tenergy 05 on backhand on my main setup for more than 4 months now. I don't feel it is spin sensitive at all (but I don't consider Vega X spin sensitive either and I've read people think it is).

Try something insensitive like rozena or any soft esn rubber and you will see that t05 is very sensitive in comparison

I agree 100% with zyu81 but would phrase it more like "not having enough exposure/training with the rubber". Some rubbers are more accessible (like Rozena) and some requires more exposure (like T05). Anything will work if you give it enough time. Exposure is not measured in weeks but rather in months if not years.

The more grippy a rubber's topsheet is, the more spin it can generate. If you are using a rubber with a very grippy topsheet that can create a lot of spin and you just put the racket out on a ball that is coming in with a lot of spin and you don't quite know what the spin is, then, you might feel a rubber is spin sensitive and the ball shoots out in all sorts of directions you did not anticipate. As someone above said, if you have that same grippy topsheet but it is now on a harder sponge, that will add the element that you will need to be more precise in the depth and quality of your contact, so, the harder sponge takes more skill to utilize. Therefore, someone who is just putting his racket in the way of the ball will feel more of that "spin sensitivity" effect that causes the ball to do funny things when you have not read the spin properly.

However, a player with decent skill who knows how to read spin can either adjust the angle of the racket and meet the spin in a way that counters the spin and uses that spin to the player's advantage. Players who use a traditional penhold BH can be amazing at what I just described and it is worth watching some of the magic they can do in how they touch the ball when returning wacky spin from an opponent's serve.

But there is also this other thing. If a ball coming at you has nasty spin and you have read the spin remotely accurately, if you contact the ball tangentially (brush contact) and you have good racket speed, and you control the depth of the contact, and you choose to contact the point on the ball where the spin will have a smaller effect (near the axis of the spin) that rubber will just do what it does as you add your spin to the ball and if you have the skill to do that, the rubber should not feel anything remotely like what the term "spin sensitive" implies.

And if you do the same stuff I described above, but choose to contact the ball where the spin will be strongest, you can give the opponent back a ball that has MASSIVE spin. And it should still not feel like the rubber is spin sensitive. You just will need enough bat speed and a useful depth of contact to take the opponent's spin and do what you want with it.

So, when you learn that you spin the incoming ball, no matter what the incoming spin, issues of spin sensitivity may not even be things you remember exist.

And if you are in the learning phase where you don't know how to spin through the incoming spin, whether taking the path of least resistance, most resistance or anywhere in between, then rubbers that are more middle of the road, that generate a little less spin but are not likely to cause you to fear the incoming spin, those would be worth using because they will help you learn how to spin the incoming ball with less of the emotional stuff that could happen to someone who keeps wondering why his attempt shot off to the left, the right, hit the ceiling or hit the table before it got to the net.

Here comes the difference between Passive play and Active play.
Softer rubbers are less spin sensitive in Passive play because of the narrow rebound angle.
Harder rubbers have wider rebound angle and in Passive play they feel more spin sensitive.
In Active play all depends on the player style and experience.
The stronger aggressive return kills the incoming spin.
The longer dwell kills the incoming spin.
A thinner brush with appropriate speed and dwell may counter the incoming spin, or use it and accelerate it with the same direction.

Directly to the OP question - T05fx would be less spin sensitive in passive play, but not so effective in active play.
T05 would be more effective in active play, but needs more precision in passive play.