Is the Dynavector XX-2 really an upgrade for me?

I have a Transrotor 25/25/60 with an SME 309 tonearm and a Shelter 501MKII cartridge and have been looking at the Dynavector XX-2. I have read that they really have some synergy with SME tonearms. However, the reviews have been with the SME IVs and Vs and I wonder whether the XX-2 is overkill for the 309.

So, 2 questions result. One, is the XX-2 worth the additional outlay considering I already have the 501? Two, if it is, will I realize the benefits on a 309?

TIA.