I've just bought the Orbe SE + SME V + Benz M2 about 6 months ago. I had contemplated about the OL RB 250 as the option. For the price, the OL RB250 is hard to beat. Don't bother with the original RB250 arm, the OL mod is worth the additional few hundre bucks! However, the Michell tables were designed using the SME V arm. The SME V have more synergy with the Orbe than the Rega arms. I think the SME was SLIGHTLY bettered than the OL Rega in terms of fuller sound, wider soundstage, and more bass. (stress on slightly) But the OL RB250 comes very close to the SME V for a fraction of the price. It's that high-end thing, you pay $$$ for that extra 5-10% increase in performance. Is it worth the money? You will have to decide. I could not pay $3200 for an SME arm, so I had settled for an OL RB250. But while I was in Hong Kong earlier this year, I found the SME V from an authorized dealer was only selling for $1800. That was cheap enough for me to abandon the OL RB250 idea, and went for the SME V.
If you decide to get the OL RB250, it might be cheaper to get the arm directly from Origin Live from England. It would be cheaper than buying the arm here and sending it to OL in UK to get modified in most cases. Make sure you get the whole mod package. Like what others said earlier, adjusting VTA would be a pain in the butt on the RB arms. Good luck!
If you decide to get the OL RB250, it might be cheaper to get the arm directly from Origin Live from England. It would be cheaper than buying the arm here and sending it to OL in UK to get modified in most cases. Make sure you get the whole mod package. Like what others said earlier, adjusting VTA would be a pain in the butt on the RB arms. Good luck!