I can't comment on the Pentax's optics, but I agree that it's a very good price and if for some reason, you don't like it, you flip it and get your money back and then some.
The price of the 8x30 SLC has gone up to around $1,100, but I still see some stores offering it at the anniversary price of $899, so price wise, $850 ain't bad, but it's no bargain. However, the SLC would hold its value longer than the Pentax if you also bought it as its full price.
One major difference between these two that surprisingly, nobody mentioned, is the position of the focusers. The 8x30 SLC has the focuser near the objectives, which I personally find objectionable!
While my friend Steve has no problem using his ring finger to focus, I do, and I agree with the comment above that it is harder to achieve fine focus with the SLC. Not only because of having to use my ring finger, but also because the focuser turns a bit harder in one direction than the other.
However, if those are not issues for you, the SLC does some things very well. The eyecups are the best I've tried for my eyes. If you have deep set eyes, there are none better than the SLC.
Aside from the position of the focuser, I really liked the ergonomics. The shallow thumb indents help me support the bins with my thumbs, something I usually can't do with most closed bridged roofs, particularly midsized ones, where I end up wrapping my overlapping thumbs around the bottom of the barrels.
I did compare the SLC to my 8x32 SE, and while I did not do a resolution test (Steve might have since he has both bins and a resolution chart and booster), just eyeballing them, the SE is probably a bit sharper, but then again, it has been sharper than any other midsized roof I've compared it to, but in this case, not by a wide margin. The SLC is sharp enough.
The color saturation and contrast are much improved over earlier models and so is the color bias, which is more neutral than the older models, which had a yellowish bias.
The rubber armoring is quite tactile and the black spongy rubber bridge is nice to sink your fingers into.
The edge performance is quite good if that matters to you. And the wide 8* FOV gives a very open feel to the view.
For a midsized non-ED roof, the CA was surprisingly well controlled. No real need for ED glass here.
I found the views, while not as 2-D as the 8x32 LX, still somewhat compressed, but almost every midsized roof looks that way to me. The only midsized roof I've tried that doesn't show this degree of compression was the 8x32 EL, but that costs nearly as much as a full sized alpha. Also better handling on the EL for my big hands.
The other negative about the SLC is its longer than average close focus vs. the Pentax ED and most other 8x32 roofs out there today. If you do a lot of close-in birding, you will prefer the Pentax.
As long as the Pentax came with a good warranty (hard to beat Swaro in that regard), I would go for the Pentax ED. At that price, you're getting a bargain.
Given other choices and bit deeper pockets, I'd prefer an 8x32 EDG 1 refurb or leftover for $999. Open bridge like the EL, better ER, ED glass, and from what I've read, better
perception of depth like the EL too.
Brock