I had wanted to try the Boston the mat, as the light but rigid interface jives with Rega philosphy. But while Boston Audion still maintains its website (last I looked, which was awhile ago), they had quit selling audiophile products by the time I was ready to buy one.
Softer mats soften the bass. I agree with Alec124c41 that the stock mat sounds, well, woolly in the bass, and that a basic cork mat is a nice upgrade. But the felt is warmer and more expansive, which can sound more natural. Listener preference will dictate.
Even so, I am of the opinion that felt doesn't belong on a high-end turntable. On a Rega 3, sure. On a Rega 7, 8, 9, 10? No. Why Rega go to the trouble of machining an ultra-rigid ceramic platter for their top table, and then top it with a felt mat doesn't make sense to me. (Some people have the same issue with Wilson speakers - all this exotic material in packages generally costing tens of thousands, with wool felt glued to the baffle? It looks like some kid's cut-and-paste project.) I know Rega say the felt becomes functionally firm under the weight of the record at the point of the stylus interface, blah-blah, but come on? That sounds like a nice thought experiment for a grade schooler's physical science class.
The thermoplastic mats and platters (acrylic and delrin, Achromat) seem to do a better job with static. However, they are not impervious. I used to wipe the big acrylic platter on my RPM 10.1 with an In the Groove roller before playing to remove dust, but it eventually charged the platter. I stopped using it, and after swabbing the platter with distilled water a few times, the charge neutralized again.
I also like Herbie's Way Excellent mat in place of the felt. I have never had a problem with static with that mat, but being a softer mat, it can lessen bass impact (slam) in some systems. It is similar in concept to the Achromat, but Herbies is a soft (I believe silcone) foam, whereas the Achromat is (I believe) a firm (thermoplastic) type foam.
Keep us posted. Hope you find an easy solution.
Rega P25-24V+TTPSU, Denon DL-103, Michell Technoarm, GT Reference Subplatter & Acrylic Platter; Pro-Ject RPM 10.1, Ortofon 2M Black; Musical Fidelity kW Phono, A308cr Pre-, Power & CD; Cardas Gold Presence Phono, IC, Gold Ref Speaker & PCs; JMlab Electra 915; M&K 700 MX