As for my take on this, Charles says it best in his post:
Without exception each account where someone has heard or owned both models they unequivocally say that as good as the Double Impact is the SE is the superior speaker. If you can comfortably afford the SE I’d suggest going that route. Decide what type of amplifier sound you most desire (as you’ll heard it with this speaker). My philosophy is get the best that you can responsibly afford and don’t look back.
As for your question on solid state and more output power:
I drove the DIs with the Spread Spectrum Technologies Son of Ampzilla II It's a Class A/B amp with 220W into 8Ohms; before moving to the Pass Labs XA-30.8
I have a T+A PA 3100 HV being delivered next week for an in-home demo. I'll report back as it will be my first go around with much higher power into the SEs.
Even though I am using Solid State amplification, and very happily so with the SEs, my primary recommendation would be Tubed Amplification for the SEs. With the DIs, either or.