The blade stock is a hair thinner than the Delica (2.286mm vs 2.50mm), but the way the blades are ground the Delica (note the "step" where the grind actually starts on the Delica - 2.18mm by measurements ) is actually thinner. That's the FFG version, not the sabre ground. I compare it to the Delica because it's what I have lying around, roughly similar, and there's a good chance you're familiar with one. The Bugout is still an excellent slicer. I use mine on cardboard quite a bit, and while my Delica cuts it better, the Bugout still cuts it very well. You won't have any problems with apples.
There's perhaps better apple slicing EDC knives out there; the Delica is ground thinner, as I mentioned, but the blade is short. The Bugout's blade isn't long enough to cut a larger apple in half in one "chop" either, but it's longer than the Delica. An Endela or Stretch might do you better in that regard, although the blades are a bit thicker.
I can't speak for the Grivory handles on the Bugout, as mine is a 535-3 with carbon fiber handles. Grivory* is like Zytel*/FRN, although perhaps a bit stronger/tougher. It's plastic, and will feel like plastic. One common complaint about the Bugout is that the handles have some flex if you squeeze them. There's no liners past the inset ones to house the AXIS mechanism. This saves weight, keeping it under 2oz. The flex is probably not an issue for regular EDC use, although it might bug you just because that sort of thing bugs people like us. This makes the Bugout a bit of an enigma or contradiction. It's a cheap premium knife, or an expensive budget knife. The obvious fix is a higher end version, or getting custom scales, but that can push the overall cost past what you can afford or beyond what you might consider being "worth it". Personalization goes a long way though.
I don't have a Mini Bugout, but having the same blade thickness in a smaller blade means it won't slice quite as well, and obviously the shorter blade won't make apple cutting easier either. I like the size of the regular Bugout. My hand (L-size gloves) fits perfectly within the contours of the handle for a full 4-finger grip. The handles are thin (at least, on my CF one they are - I don't know if the Grivory ones are thicker), so it's good in the pocket in that regard (essentially the same as a FRN Delica). It is a touch broad though, although not as broad as a Delica. If you're interested in the Mini Bugout, I'd suggest also looking at the 945 Mini Osborne (mini 940). It's a small bit longer and heavier, with a slightly thicker blade (thinner than the 940), but depending on your preferences, might "pocket" better.
Whatever you do though, buy only from authorized, respected, well-known dealer (ie: not Amazon, and not eBay unless you trust the seller). There are a TON of counterfeits of the Bugout and other Benchmades, and it's very possible you could receive a fake that someone bought from and returned in place of the original.