I've played with Boost TC when I started playing TT again after a 14 year gap. I used to play with speed glued Mark V GPS, and when told the speed glue / boosting was not allowed anymore, I tried Boost TC.
The feel was great, and I found this 38 degree hardness rubber to replicate the feel I had with my old Mark V GPS.
The soft sponge really allowed good spin and sufficient speed. Unfortunately, the bounciness is such that you lose a bit of control on short balls.
Also, as this is now an old rubber (one of the best of the first generation tensor though), they do not last very long. The spin potential is great at first (while nowhere near current top rubbers), but dissipates very quickly.
It's not the cheapest (nor the most expensive).
It is a light rubber, with a low to medium throw.
7 years ago, with the celluloid ball, it was a good rubber. It is now an outdated rubber, as others have more speed, more control, more spin, same softness, last longer, and can be found as cheap or cheaper (e.g. Xiom vega europe, Bluefire JP3...).