I have two IS binoculars:
Kite APC 16x42
Fuji 12x28 TS1228 Techno-Stabi
Here is a brief review of them, with a comparison.
First the commonality: the stabilization works very very well in both of them; well enough that they are usable when I am a passenger in a car.
Optically, the Kite have a larger apparent field of view, and give noticeably more detail. In intuitive terms, I would say that the step up from 8x to 12x is twice as large as that from 12x to 16x, but the step from 12 oto 16 is certainly noticeable. The Kite have very good design: they use AA batteries, their housing also stores spare batteries, they are water resistant, and they have a very handy orientation-sensitive switch that turns them off when pointing down. The drawback is that while light for a 42mm with stabilization (under 800g) the Kite are somewhat large, and have an unwieldy bag, so they do take their space in your backpack. Also, I find the Kite do not have sufficient eye relief to be a pleasure to use with sunglasses.
The Fuji are very light (lighter than my 8x32 Ultravids!), and also very sharp. They use expensive CR3 batteries, and they do not have the orientation-sensitive switch, but on the plus side, they have excellent eye relief, so that using them with sunglasses is a pleasure, on par with my Ultravid 7x42. One might think the exit pupil is rather small, but the stabilization really helps, and it's really easy to position these binoculars even when wearing glasses.
In practice, I find they fill two different niches.
If you want to observe far-away coastal birds, the Kite are great. You take them as your main binoculars, and they will give you plenty of detail.
On the other hand, if you are hiking, and want a pair of higher-power binoculars to ID far-away birds, the Fujinons are the better choice. They are much lighter, smaller, they fit better in the backpack, they are easier to carry alongside the main binocular, and if you are hiking in the sun, they are very easy to use even if you are wearing sunglasses.
I would not take the Fuji as my main binoculars for hiking; the 12x make the DOF too shallow and the field of vision too small to quickly find active birds. But as an auxiliary pair to ID distant birds, they are wonderful.
Kite APC 16x42
Fuji 12x28 TS1228 Techno-Stabi
Here is a brief review of them, with a comparison.
First the commonality: the stabilization works very very well in both of them; well enough that they are usable when I am a passenger in a car.
Optically, the Kite have a larger apparent field of view, and give noticeably more detail. In intuitive terms, I would say that the step up from 8x to 12x is twice as large as that from 12x to 16x, but the step from 12 oto 16 is certainly noticeable. The Kite have very good design: they use AA batteries, their housing also stores spare batteries, they are water resistant, and they have a very handy orientation-sensitive switch that turns them off when pointing down. The drawback is that while light for a 42mm with stabilization (under 800g) the Kite are somewhat large, and have an unwieldy bag, so they do take their space in your backpack. Also, I find the Kite do not have sufficient eye relief to be a pleasure to use with sunglasses.
The Fuji are very light (lighter than my 8x32 Ultravids!), and also very sharp. They use expensive CR3 batteries, and they do not have the orientation-sensitive switch, but on the plus side, they have excellent eye relief, so that using them with sunglasses is a pleasure, on par with my Ultravid 7x42. One might think the exit pupil is rather small, but the stabilization really helps, and it's really easy to position these binoculars even when wearing glasses.
In practice, I find they fill two different niches.
If you want to observe far-away coastal birds, the Kite are great. You take them as your main binoculars, and they will give you plenty of detail.
On the other hand, if you are hiking, and want a pair of higher-power binoculars to ID far-away birds, the Fujinons are the better choice. They are much lighter, smaller, they fit better in the backpack, they are easier to carry alongside the main binocular, and if you are hiking in the sun, they are very easy to use even if you are wearing sunglasses.
I would not take the Fuji as my main binoculars for hiking; the 12x make the DOF too shallow and the field of vision too small to quickly find active birds. But as an auxiliary pair to ID distant birds, they are wonderful.