In all honesty, my initial reaction was the same, but having now used the X-Preg a fair bit, I can confirm it is far superior to the EasyPreg.

It is a bit of a shame about vinyl ester, I'm in the same boat with having a lot of vinyl ester tools that aren't going to do me much good anymore. I don't have access to Unimould, but I use the Reichold tooling system which is very similar, and results with the X-Preg aren't actually terrible. They do have some pinholes, so it isn't 100% perfect. Gloss and everything else is actually better than the EasyPreg, so parts do still come out looking very nice. If that is unacceptable then you will need to make epoxy moulds, but I dare say most people would actually still be very happy with the results using X-Preg in a vinyl ester mould.

As for making complex split moulds with the tooling pre-preg, it is only really a couple of extra steps abd of course some more material costs. If you already have moulds, then it's as simple as just laying up a laminate with epoxy resin and copying the entire mould including the flanges and barriers. Then you can use those pieces to make the pre-preg tools. If you need to make new moulds, then you do need to make an initial splash mould in the ordinary fashion, then the epoxy patterns, then the pre-preg. So it's a bit of a pain in the ass, but not really that much more drama if you are actually getting use out of your moulds - for one-offs it probably isn't worth it, but then you can just make your tools via hand lamination with high temp epoxy.

Ok , so it is possible to use the xc110 on the unimould system only u might have some pinholes ?
I made parts  with the varipreg  only in the unimoulds and got good parts also little pinholes but nothing to bad .

Will try some xc110 and see what there happens but making all new moulds in prepreg wil be verry expensive I think .

It should definitely be possible, but I'll let EC confirm. The chemistry between the Reichold and the Unimould will be extremely similar, so I would be very surprised if you didn't get the same results as me. I'll post a picture of my results in a bit.

Any pictures yet ?

Sorry mate, totally forgot! Have got plenty of photos, will upload some when I got home this evening.

These are some parts that my students made in a course I ran a few weeks ago. The little speed shapes and the love heart are X-Preg cured in vinylester tools at 90°. The mounting boards are infused, not pre-preg.

looks good , what cure cycle did you use ?

Cure schedule is exactly as the TDS outlines for the low temp schedule.

ok only negative is that it needs to be 10H at 80° what is real long time .
Is it possible to use the varipreg 450 as a bcking layer on the xc110 ?
And is it also possible to use 2 layers of XC110 only on parts for parts who need to be really light and have no real strenght needed ?