- The 2.15mm 39° is the best version I´ve tried. 2.2mm is too much, gives a bit more speed but control is lost.

- When boosted it becomes much more dynamic, in speed and spin, but again control is lost.

- If you want to use this rubber you´d better have an excellent physical condition, and also great stamina. Because it demands it, you might be able to play the best with H3N in the first match of the day but, in a tournament, for example, in the 5th or 6th match you will produce nothing if your stamina is not ok.

- Being fit is not enough to use it. You can´t be lazy when execute the attacking strokes. A full swing is needed, as well as a quick recover.

- It´s more difficult to use H3N than ESN rubbers. H3N is more dangerous but only when strokes are properly executed.

- It´s not for me. I can make a full and fast swing but definitely can not recover fast enough for the next shot. And I also can not keep the quality of strokes for more than 2 matches, my body says no.

Anyhow, I recently started using H3 Prov blue sponge for the first time after having used various tensor rubbers (T05, MXP, G1, etc.). 

My H3 is 40 degree and is boosted with 3 layers of FTL. I must say, I really do like the control it offers in the short game, but as someone said above, you need to have a proper stroke to generate the spin. This mean, you have to have a solid footwork so you can get into position. This is extremely difficult but it also forces me to be proactive in my footwork. I'm enjoying it so far and my game has improved. 

What are 'grippy' rubbers? vs. tacky

grippy are European style rubbers. You make the spin with grippy rubbers when the ball hits the topsheet compresses into the sponge and because of the upward movement of the racket the ball rolls and gets spin. 

Tacky rubbers are Chinese style rubbers. They have different chemical structure and the ball sticks to the topsheet. You can litterally lift the ball by pressing the rubber into the ball. When the ball hits the upward moving rubber it sticks for a moment to it and bounces back and gets the spin. So they differ in how they make the ball spin. 

Grippy rubbers tend to have softer sponges and tacky tend to have hard sponges. Also tacky rubbers are slower and because of harder sponge more linear and need more power to utilize them properly, so it's more common to use them for FH as FH is much more powerful

It depends from player to player, but I had a similar situation. I've been using H3Neo (commercial) for a long time and then I got Palio for free. So I put them on to give them a try. Needed some time to adjust, played for some time and after the rubber was done returned back to H3Neo. Again, needed some time to adjust, but in general didn't have any problems...

DO NOT USE H3. Unless you are professionally getting trained. You need to waste time boosting it, reglue it, then every 2 weeks it plays differently, then you start thinking about "what if i got blue sponge will i play like CNT" Then buy all sorts of blue sponge, fake/ real whatever. Then you will try different booster on effect. It's a waste of time and money. Just use jap/euro rubber and be done with. 

To each his own. Your statement does apply to majority of people, although for me H3 improved my game. You don't need to boost it every 2 weeks with FTL. Once you find the right supplier, there's no concern about getting fakes. Getting provincial version means higher quality control. Blue sponge version is a bit "crunchier". 

People just EJ as much with euro/jap rubbers, not to mention the cost of a butterfly rubber can literally buy you five H3Neo. 

It is just the hardness that makes it too difficult to use for amateurs. 95% of eurojap rubbers are well below 50 degrees. H3 starts at 51 degree in 39, its softest common version.

So just get a softer h3 and problem solved.

or buy H3Neo which stands in the middle between Euro and Chinese rubbers. Not as tacky and not as hard 

I vaguley recall seeing a video on YouTube comparing H3 and H3N. I remember Neo came out more tackier than regular. 

As zeio has mentioned, there is no difference nowadays other than the protection  layer. So, if you boost provincial or higher, no need to get Neo. 

I find boosted H3 works great with the ABS plastic ball.

Be sober