If you are talking about the new Vaquero built on the smaller frame, then both it and the Colt will shoot the same SAAMI spec .45 Colt loadings. The previous Vaquero built on the heavier frame is the one that can shoot the hotter loads.
The Vaq and the Colt are similar, but different. I don't have a Vaquero, but I've handled Colts and currently own a Cimarron Model P, which is a truer replica of the Colt than is the Vaq.
The Colt uses leaf springs. It does not have a hammer transfer bar safety like the Vaq, meaning you can't (shouldn't) carry it with all 6 chambers loaded and the hammer down on a live chamber. The reason is, the Colt's hammer has the firing pin on the hammer, so when the hammer is down, it's pressing into the live primer, which is not a safe condition.
The Vaquero (and all Rugers) uses coil springs. It has the hammer transfer bar, meaning it's safe to carry the hammer down on a live round.
The Colt has a different trigger mechanism. To load the Colt, you have to bring the hammer back to half cock, then swing open the loading gate. On the Vaq, you can just swing open the loading gate with the hammer down to load the cylinder. The Colt has three positions the hammer can be cocked to: "safe", half-cock, and full cock. Cocking the hammer on a Colt will give you four "clicks", which some would say spell C-O-L-T.
If it were me, and I wasn't just dead set on having a Colt, I'd get a Ruger Vaq or a Uberti/Cimarron for roughly a third the price of the Colt, and see how I liked it. I like Colts, and I own a 1911 Colt Commander, and I plan on owning more, but I have a hard time couging up $1200 for their current model SAAs.