I collect original Vaqueros and I own more than a few. I have blue, stainless, CCH, short barrel, long barrel, Birdshead, plow handle and Bisley. I also have three New Vaqueros. Every Vaquero/NMV I own is 45 Colt.
Two of my NMV are my CAS guns. They're stainless 5.5" and I've have no idea how many thousands of round I've shot through them. The actions on both are like butter but I haven't done a thing to them except shoot the crap out of them and occasionally clean them. The reason these two are NMV and not original Vaqueros is because when I started shooting CAS I bough these two used and they were my first Vaqueros. I see no need to replace them simply because they happen to be NMV.
My other NMV is a 7.5" CCH framed 45 Colt. Even though I prefer original Vaqueros over NMV I bought this one because they didn't make a whole lot of NMV with CCH frames and 7.5" barrels.
OTOH, I'm completely enamored with original Vaqueros and I'll buy just about every one I find that's a little unusual and/or in excellent condition. I don't own any that are rare or super valuable but most of mine are not the run of the mill 4 5/8 to 5.5" basic blue Vaqueros. If you made me pick which my favorites are I'd have to say my 4" blue/CCH Birdshead and a consecutive serial numbered pair of 7.5" blue/CCH plow handled guns. All three are, of course, 45 Colt.
I prefer original Vaqueros for several reasons:
1. They don't make them any more.
2. Ruger QC was a little better back then.
3. Even though I don't shoot ROL in my original Vaqueros I could if I wanted to.
4. Original Vaqueros can be found in some pretty cool configurations.
5. It's a finite set of guns and I enjoy learning everything I can about them and trying to become a subject matter expert.
6. While they don't make them any more they're still available and every now and then you can find some really nice examples for sale.
7. As collector items they're still affordable.
8. I prefer the slightly more robust feel of the larger framed original Vaqueros. However, the size difference really isn't that much so don't get hung up on it unless you know for sure you want to shoot ROL.
My recommendation is look for the configuration that appeals to you and not worry about whether it's an original or a NMV. Either one will serve you well and unless you're extraordinarily abusive your great, great grandchildren will love owning them too. One last thing, 45 Colt is the only caliber worth buying whether you choose original or NMV. Why? Because it's 45 Colt. If I have to explain it......