For optics... the Weaver is, pardon the pun, clearly the better scope. No comparison. If you're used to a Scopechief or a BSA, then either of them are lightyears ahead. I've owned three VariX IIs and do own two Grand Slams and the Grand Slam is simply a better scope and lower priced to boot. I honstly think that the Grand Slam is more similar to the VariX IIIs than the VariX IIs.
On the other hand, Leupold service is super duper top notch. I bought a rifle with a Weaver CV10 (aluminum tube, current owner's product) that was missing the rubber ring on the ocular. Emailed them asking if I could
buy a replacement, got a smart-??? response from a rep about how they can't just give away parts for scopes made 20 years ago. I asked, by email again, if I could be forwarded to another rep because he was obviously far below par for what a customer service representative should be. Never got a response. Emailed twice again over the period of a week. Finally called and talked with someone in service department who wouldn't give me their name. Said the rep I corresponded with was a fine multiple year employee and that I was asking for too much.
If asking to buy a piece of rubber is asking too much, well... I guess I'm just a really demanding jerk. One of the Leupolds I traded into looked pretty good except for a scratch on the elevation cap. I called them, and they sent one out and I had it on the scope in about four days.
But those Weaver Grand Slams sure do look good.