I think it's very important to try an 8x25 before deciding. While many people for many decades have found a "compact" size like 8x30 or 8x32 to be a great all-rounder (think that devices like the 8x30 Zeiss of yesteryear have sold in astronomical figures, and the contemporary 8x32 is very popular), I personally find that the jump to a smaller 8x25 is a great one, larger than the few mm in objective diameter might suggest.
8x25 are smaller, which means for some people are a bit fiddly to hold, eye position is more crucial, then some models have double hinge design which for some people is not as convenient for everyday use, they are dimmer in difficult light conditions and the field of view is narrower compared to most 8x32. So personally I would not consider a 8x25 as my main binocular, but only as a "specialised tool" if I really need to pack small. But then, some 8x25 are really not that small and light, and truth be told, the term "pocket" is a bit of a stretch for some models, while the 8x20 seems to be more rightly so in "pocket" territory.
Sure, there are 8x25 and 8x20 binoculars with amazing optical performance, but that doesn't take away the fact that many people find them awkward to use for long periods of time or as a sole device. So I would not sell a 8x32 to buy a 8x25 (like in exchanging a model for the other). But then everyone needs are different. When I'm going birding it's usually at least 2 or 3 hours, and some days up to 4 or 5. So in my case I would personally keep a "daily"/"go to" which I find comfortable to use. But then, that's just me. There is a quite impressive offering of very light 8x30/32 like the new Zeiss SFL, or the Nikon MHG that probably "feel" and behave like a full-size bino, while not adding a lot of bulk or weight compared to a 8x25. The Kowa you have are light at 520 g, but I feel there is a noticeable difference if you go down to 450 or 430 g binoculars like the ones I mentioned above or even the Nikon M7, Opticron Traveller ED 8x32, etc.
One can read amazing (and deserved) praise for binoculars like the Ultravid 8x20, but you have to think that it is first and foremost an 8x20. The same way you can read amazing things about the optical performance of the 7x50 Fujinon FMT-SX, but you have to remember that it's an IF monster of nearly 3 pounds.
So, as always, the main advice is just to go and try an 8x25 or 8x20 for some time and draw your conclusions in terms of handling, comfort and usability