Transparent Reference XL question

I currently have Transparent Ultra XL RCA cables between my VTL st 150 amp and 5.5 preamp. All of my other cables are Transparent Super XL's. If I trade the Ultra interconnect for Reference XL's will I hear an improvement ?
The Ultra Xl was known as the most for less $, and you might or might not like the combo. It will change the signature but the Super already has a much different sound than Ultra or Ref in your system. I would try to match the line you choose for your taste, like I chose Super XL for a Krell 300r,250cd/2 and B&W CDM7NT's. I love the rock and roll, and musical presentation with the $ considered. I had Ultra Xl on my main N802 but I still opted for something different because it was to tame for me. Happy listening :-)
Upgrade the speaker cable first to Reference with XL, it is amazing!
If you haven't addressed power filtering with a PS Audio, or Hydra then you need to address this first.
Sorry, no easy answers. You will hear a difference but it may or may not be better. I once had a system with Ultra and when I tried the reference I didn't like it as much. Better resolution but the bottom got thinner. I agree that the Ultra is your best bang for the buck.
I have found the Reference XL to be clearly better than the Ultra in all dimensions. I imagine that there will always be some system interaction that could cause others to prefer the Ultra or perhaps just personal taste. You should probably consult with Transparent. Perhaps they could help you audition a pair of XLs if you are planning to upgrade yours or buy new.
I have to agree with Rlapporte. The Ref w/xl is better in all area's than the ultra. However, Transparent says the most important cable is the source to preamp, then speaker, then pre and amp. I might upgrade the super to ultra or ref 1st. Also, ac cords make a big deal. I like transparents ac cords. I bet they will help on your VTL equip. But, here again, put the best on your source 1st, then amp or pre.

Good luck