got an offer for the 03 yz125 for a 05 predator 500

a predator 500 is a decent quad and is worth more than a YZ125.
I have some experience with preds. Basically Ive rode one around the lot at a race and it felt real nice. And if there's one thing Polaris does right its putting as much power in the frame as possible.
Now my brother does a lot more racing than me and he is a lot more active on forums so he learns about the less popular races and does some forum events. At those kinds of events, he can usually get someone to switch with him during practices or warm ups so they can feel what a XC setup YFZ feels like and he gets to try out other bikes. He traded off with someone for a couple laps at the NEMX track in Andover, OH and he had to say that the engine didn't seem to have the pull as his, didn't seem to pull out of the turns like a YFZ but once it gets into the top end, they are beasts