You may find with Transparent...moving you're % up from 3-5% is a better investment. I have found their cabling to equate to equipment changes...and their upgrade program really helps you out as funds allow.
I am pretty sure if you demo Ultra or Reference...it won't be going back...that's been my experience . If you are demo'ing a brand new cable...be sure to give it a few weeks to break in...but I suspect even with Ultra brand new it'll beat a well worn in plus easily after about 1 hour of playing time.
With a lot of "upgrades or equipment changes" I find I usually go 6 or 7 steps ahead and then 2 or 3 back in some area. With Transparent upgrades...everything advances...