I have not looked at the "new improved" VariXIII, as to image quality, so my opinion should be taken with a grain of salt.
What I'd like JDJ to state is his mission; type of hunting and terrain expected, what ranges he will be shooting, etc. It's assumed that the expenditure of more money should buy better quality. He may not need the bells and whistles, and then again, maybe he does?
As to Airbornes' question. What seems to me is that the 40mm objective is more than adequate for the majority of applications. The gentleman needs to state a case for the 50mm lens, because, as one poster already mentioned, that 2.5X8 is a real decent, general big game scope. I have, and use both the 3.5X10X40 and the 2.5X8. Hard to go wrong with either. I have 50 and 56MM scopes on some rifles and have very good reasons.
If he has a good reason, fine. If not, then I'd guess the new VariX (40mm) would be a good choice, if the optics are as good as I'm reading, above.
Whatever the choice, good luck. LB