Enjoy your new binos Evan. I get to use my brother's 8.5x42 Fieldpro regularly and it's outstanding; never fails to impress even though my own binoculars are pretty decent themselves. You don't have to use the thumb indents (and I never do), I do like the way you can wrap your hands firmly around the open bridge, and I find the 8.5x magnification gives me a slight but noticeable increase over 8x while not being as shaky as 10x. Image quality is exceptional even by today's standards, it has pretty much everything you could wish for. My brother's example, at least, has to be the sharpest handheld binocular I've ever used or even tried, with tremendous detail and definition, very bright to the point he has to wear sunglasses in some conditions, and I like the much-derided (at least by certain folks on here) flat field which works really well for the birding I do. It's a great birders' glass almost no matter what birding you do, a true modern day classic - easy to see why it was popular from its first iteration. It and previous versions are a large part of the reason why Swarovski is the best-selling alpha brand and IMO it is a worthy inheritor to the mantle of the great oldies like the 7x42 Dialyt.
Opticron did a good job with the Aurora range (
I liked the 8x42 demo at Birdfair quite a bit more than the 10x42 which I found quite difficult) but even they would wholeheartedly admit they are not aiming to compete at that level. The Aurora gives you everything you really need for birding but its lower price than its competitors (Zeiss Conquest, Monarch HG etc) reflects its build quality, or at least
perceived build quality to me, not being at the same level; and while I think its image quality
is in the same ball park as those, and certainly good enough that it'll be your birding knowledge rather than the optics that make the difference in getting IDs, it's not the best in that group.
I've always liked to have the choice between 8x and 10x and I think the 8x42 Aurora and something like a 10x42 EL would have been a great combination to have; the larger exit pupil of the 8x42 Aurora should make eye comfort easier, while the superb quality of alpha optics really make themselves shown in 10x, which I still prefer for longer distances. But the 8.5x42 is, absolutely without a question, great. You quite probably don't need anything else - my brother doesn't - and it wouldn't surprise me if you sold on your 10x42 Aurora for funds to put towards something like a good scope. IMO there's a good reason why Swarovski went back to 8x and 10x for the NL range - they realized they'd sell more binoculars!