OK, so I am going to eat some crow here...I got a 500mm copper Kaneshin watering wand at the beginning of April and it's pretty terrific.
Pic of my rig is below.
I got it mine from
North American Satsuki Bonsai Center. NASBC also had an even larger version of the same wand, copper and less expensive chrome. I got copper, well, because I'm a sucker ;-) and like the look and feel. A friend of mine later bought the largest chrome version at the PBA show in D.C. It works just as well.
Despite the complications of installing it (more on that later) and cost ($80--s
horter chrome versions can be had for $20-$30--some with built in shut off valves), I've found it to be without a doubt the best watering utensil I've ever used. The longer length allows easier watering even in hard to reach pots. That said the cheaper, more easily installed wand offered through Joshua Roth and other places remains very good and a lot less expensive. I still have mine as a back up.
I've using been the Kaneshin for a month now and have been impressed with the extremely fine flow of water that doesn't disturb or wash away bonsai soil-unless you turn the waterflow on full tilt at the faucet. The Kaneshin's rose has triple the holes or more than the Roth and IMO is far superior to any western facsimile I've used, like Haws or Dram.
Installing it, however, can be a chore. Since it has no threaded end and is jammed into the cut end of a hose, it requires some thought and additional outlay of $ (not a lot though) if it's going to work correctly. First you need an additional (sacrificial) flexible garden hose--I got a 10 foot one at Home Depot for $20, hose clamps (I used steel plumber's grade, but you could probably get away with big zip ties--but those could deteriorate in the sun over time), and a decent brass shut off valve (which run about $10, the clamps are $4 for a pack of ten).
A word on the sacrifice hose--I was tempted to pay $5 for a cheapo hose. However in looking at the type of plastic used in cheap hoses, it was obvious they weren't going to work well, since they tended to be made of less flexible plastic. Most of them also had smaller diameters. Both of those things could damage the watering wand by bending it.
You have to cut the female end of the sacrificial hose off about a foot or so from the threaded end. That leaves a foot long (you can go shorter if you choose) pigtail of a hose with a female end. I chose to install a shut off valve between the modified hose on the wand side and the male end to the actual garden hose, allowing water flow to be adjusted quickly and easily without having to kink the hose with one hand and water with the other.
After being a skeptic, I'm a convert. Should not run my mouth before actual experience...