Can't help you with Dyna 1.8 but 1.3 sounds and images definitely better than RM33i I havn't heard 25's but can tell you that they probably as Dynas need locomotive power to drive them.
Vandys in general are too slow for rock and metal i.e. it seems that they don't stop the driver ontime causing drums to sound longer than they should. I had Vandys 1c and even after upgrading to more powerful amp Bryston 3b-st after Creek 4330R they still didn't do the right job with dynamic rock and fusion jazz. When I listened to larger Vandys 2ce ones with even more powerfull Plinius 8200 they had this problem even larger. So my suggestion is to wait untill you grow to Vandy 5 that I think one of the most successfull speakers in $25000 range(Warning ultra-ugly with no cover!:-)).
Many folks love Vandys with tubes but that can also be an issue with many more speakers that do tend to benefit from tube drive(I love them better with tubes as well).
Vandys in general are too slow for rock and metal i.e. it seems that they don't stop the driver ontime causing drums to sound longer than they should. I had Vandys 1c and even after upgrading to more powerful amp Bryston 3b-st after Creek 4330R they still didn't do the right job with dynamic rock and fusion jazz. When I listened to larger Vandys 2ce ones with even more powerfull Plinius 8200 they had this problem even larger. So my suggestion is to wait untill you grow to Vandy 5 that I think one of the most successfull speakers in $25000 range(Warning ultra-ugly with no cover!:-)).
Many folks love Vandys with tubes but that can also be an issue with many more speakers that do tend to benefit from tube drive(I love them better with tubes as well).