Hi Latej,
At present my preferred BH rubber is Rakza Z or R48, probably Rakza Z over R48, but I'd be more than happy to use either!!
I use both of these in 2.0mm not max sponge thickness.
The R48 seems a little faster, feels slightly harder, even though the sponge is softer!! Strange, but that's the feedback I get. Especially when fine brush slow FH loops v backspin, the Rakza Z feels softer, but both have pretty soft thin top sheets.
I put R48 (FH & BH) on a Donic Dotec Ovtcharov off blade, Rakza Z on both a Nittaku Acoustic & Nittaku Acoustic Inner (FH & BH), which are also rated as off blades, the inner is slightly faster, for a similarly played FH topspin the ball travels about 200 to 300mm further, well that's my estimate!!
Both rubbers produce high spin levels, both have highish throw angles and are good for top spin openers v backspin.
Personally I think that the R48 really excels with drives and flatter hits, it's very crisp indeed. But it's still great for looping!!
H3 Neo Provincial 37 degree 2.15 mm sponge, boosted with 2 layers of Seamoon, sealed 1 layer revo no3 glue before booster applied. When gluing I applied 3 layers of glue to rubber and 2 to the blade, which is a BTY Maze Magic on BH side
So comparing the H3 Neo to the R48 and Rakza Z (RZ)
H3N felt great on BH, it felt like the ball was grabbed by the top sheet, felt like the ball 'sunk' into the top sheet!! Spin was great, speed not quite as quick as R48 or RZ, lower throw angle, kick better than both R48 & RZ, ball springs forward. Control at the table when blocking and pushing was good, as you'd expect with tacky rubbers, I would say that H3N and RZ are better (slightly) than R48 in this department, for faster crisp blocks the R48 has it!!
After boosting the H3N has more 'bounce' than RZ but less than R48 when you do the bounce test.
Now, after a couple of months the H3N has lost its boosted feel, still feels softer than 40deg H3N, bounce has returned to 3 or 4 bounces then stops dead!! Tackiness is still the same, H3N has more tackiness than RZ, but I think RZ looses some tackiness, straight out of the pack the RZ was similar 3 or 4 bounces then dead. R48 has no tackiness to speak of.
I think R48 and RZ are easier to play with away from the table when playing BH top spin and BH looping, I just have more confidence with these 2 over the H3N , RZ & R48 have 'easier' (some may say lazy!!) speed!!!
I like all 3 rubbers!! Could happily play with all 3, they are all great rubbers!! One thing I've learnt trying out different rubbers, it's pretty hard to find a really bad one!! At the end of the day it comes down to the players personal preferences!!
By the way DON'T IGNORE SKYLINE 3 PROVINCIAL BLUE SPONGE , there's another thread asking If skyline 2/3, TG2/3 is dead!! This is another great rubber, I put it on the Maze Magic alongside the H3N 37. Boosted in exactly the same way way as described above, it is basically faster with very similar attributes to the H3N, fantastic for fast FH loops, the other thing I noticed was that the boosting affect seemed to last longer, but this is likely because that's what Skyline rubbers are meant to do?? All I know is that when doing the bounce test (when the H3N boosting effect had worn off) I was expecting the Skyline to be similar, it wasn't 5 - 6 bounces, felt like a slightly muted new boost effect when looping!!
If I were to boost in future I would try Falco Long Term booster, 2 or 3 coats. Just because it lasts longer!!