i have a keeler set and while i can say the optics of the oscope are quite good, the -20/+20 switch is fairly annoying but it's rare that you have to enter than range but still, it's annoying when you have to.
many people have been having a lot of quality issues with their keeler sets at my school though, i don't know if this is just a bad shipment or whatnot but a handful have had major problems, myself included. and another bunch had minor ones, like new kits coming with dead bulbs (which isn't a big deal, but come on, in a new kit?)
my retinoscope had major problems though, the streak was not focused and there would be large hooking at the end of the streak and also there was a halo around the streak.
also the tip of my transilluminator came cracked, this was dismissed as "normal" by the sales rep, which is kind of farcical if you ask me. the hooking i described previously on my ret scope was also categorized as "normal", and i mean the hooking was bad, almost forming a "C" shape. anyway, after several emails, the rep finally took it in and sent it for servicing, which took about 1.5 months...
and nothing was done about the transilluminator. some of my classmates have had to have their oscope heads replaced or serviced and the hooking is fairly noticeable on many of their ret scopes as well, while i know this does not affect your findings when you perform retinoscopy, it's just the concept of it being there when it shouldn't be. that's like buying a new car and having the brakes squeak all the time, sure it might not affect the performance but it's really annoying and it's something THAT SHOULDN'T happen. and while the cost of these kits is not astronomical we still paid a fair bit of money for them, i would just expect a better quality product for our purchases.
anyway, that's just my rant and i needed to get it out there becuase the service and quality of keeler is subpar in my experience, but the instruments themselves, when they work properly are quite good.
some of my classmates have been having quality issues with the WA kits as well, heine seems to be the brand that has been ok so far, but who knows? maybe you guys have had a lot of problems with them. so far i prefer the heine kit, even if i think the oscope has clunky controls. the optics are excellent and the build quality is there.