I'm by no means an expert in binoculars, but given my limited experience I'd say that they're pretty good both in terms of image quality and build quality. I've compared them to both my Zeiss Conquest HD 8x42 and Opticron Discovery 8X32 WP PC.
More and more I am convinced of two notions that are often pointed in this forum when it comes to optics:
1. You get what you pay for.
2. Differences in quality get smaller as soon as the price gets higher (that is to say, the difference between a 50 € and a 150 € pair of binos will be a way bigger than that between a 800 € and 950 € pair of binos, although the price difference is the same, 150 €).
- Build quality: the binos feel really sturdy and solid. The quality feeling (to my eyes) is at the same level of the Zeiss. The rubber armor is really rugged and the grip is reassuring. I was comparing the Conquest and the Kowa side by side yesterday at dusk, observing Eurasian stone-curlew among vineyards, and obviously the Zeiss has a brighter lens (I was surprised that it is not a "much" brighter lens, or an "incredibly lighter" lens). The Kowa are obviously a little less bright, but they have a very good contrast. Maybe one of the clearer differences is the % of the view that is flat/usable. In the Kowas this is smaller, obviously (and gets even smaller in the Opticron).
So, given the prices I payed for them (in € Zeiss 800, Kowa 350, Opticron 250) I think the Kowas are the best value for money of the three. I haven't looked through the Zeiss Conquest HD 8x32 (mines are 8x42), but given the price difference (the Zeiss are roughly twice the price of the Kowa) IMHO you really have to like the Zeiss over the Kowa to invest that money. So we came to point number 1 and 2. I am not saying that Kowas are on the same level as the Zeiss (they belong to a lower category), but the value for money (price/performance) could be more than satisfying for someone interested in birds but who doesn't want to break the bank.
- Pros: brightful, good contrast, build quality, value for money
- Cons: heavy and not the smallest (compared to the Opticron, for example)