Squier VM Question

I would say the bridge, and control knobs. The Jag bass has four...IDK why...maybe it has a preamp? The P-Bass style has only three, VVT, I assume.

The Jag has a jazz bass neck, according to its description while the P-Bass style, well, has a P-bass neck?

 

Most of the difference is probably in the neck and the bridge. The P likely has a nicer finish on the neck and it has what appears to be a "high-mass" bridge. The pickups may be nicer as well.

That said, I have a fretless VM P bass with that same Agathis body, and I wouldn't buy another one. It's an ugly, inconsistent wood that is super soft and light. I like a harder, heavier body (not that basswood is hard, but by comparison...)

Lastly, as an owner of a number of VM and CV Squiers, I'd advise against buying them online, in case that's your plan. The decent ones are just about the best 'bang for buck' basses out there, but the QC can be spotty and plenty of bad ones are made with wonky necks and frets. Make sure you play whatever you're looking at first to avoid lemons...