Radical plays stiffer and hits a bigger ball with a shorter swing for me. The speed mp doesn't have enough mass for its flex for me. I get arm pain whenever I play it stock with poly, and I don't with the new radical mp. I also feel a bit pushed around with the speed mp and don't with the radical. I'm used to heavier, flexier frames, though, and when I demo'd a speed mp at my specs, it was quite nice and the pain issues disappeared. If it's in your weight class, it's worth a demo. The radical probably is too...it's a bit firmer to me and provides a crisper response and feels more stable for me in stock form--not unlike older, stiffer blades (the first BLX one specifically comes to mind). Both have great feel and a traditional flex, unlike the Blade v7.
On your tennis elbow issue, listen to your physical therapist and do your home program. String with natural gut even if you're a string breaker. The extra $20 or so in the short term is incredibly worth it for your arm health in the long term.
If you can get an extended demo on any frame or find one you really like, string it with some syn gut or cheap multi and put stencil ink over the whole stringbed. Go out for a hit and see where the ink wears off. If it's mostly worn in a single area near the center of the frame, you can hit the sweetspot of that frame well and minimize shock to your arm. Whether specs have a huge impact on this is a completely different conversation, but it's an extra step you can take if you want more peace of mind and have the time.