Both are pretty good. A couple of years ago the VX lineup was upgraded. Todays VX-1's are essentially older VX-2's and the new VX-2's are essentially older VX-3's. I've not tried the new Terra, but do have a couple of older Zeiss scopes, a Conquest and Diavari. The VX-2 is 95-99% as good and a LOT less expensive, lighter, and with more eye relief. I cannot imagine ever actually needing more scope than a current VX-2.
My experience with the VX-1 is limited to a 1-4X20 scope so it is hard to make a fair comparison to the 3-9X40 VX-2 I own. I'd spend the extra $100 for the VX-2. I probably don't need to, but even at $300 I think the current VX-2's are a bargain.
