I believe the difference is supposed to be the coatings are better on he VX-III. I have a few VX-II's (1-4 power), and a VX-III 1.5-5 on my 6.5 CZ. Both are nice, the 1.5 is REALLY nice. The VX-III is a good bit more money. I got mine new in the cellophane off E-bay for under 300$ which is the biggest reason I ended up with it. If you have a little time, try E-bay. I threw out all my cheap scopes in a fit last year, and replaced 3 or 4 of them with Leupolds, all for quite a discount. Have fun, and I bet that .375 shoots great.