I have 2 KHS tandems, a CR/MO sport for the kids, they liked it so much and were having so much fun I got ALU version for myself. They are well spec'd for the money the alite is an 20/16 I think which fits me at 6'2" and all my family who range in hight from 4'10" to 5'4". I have ridden the Alite through 9 states, on the highway and for two months on the great divide, plus a lot more local and gravel road miles.
Interestingly we wore out 3 sets of front wheel bearings, a number of chains and broke 1 spoke nipple on the front wheel, and a number of tires. For 4-5 months of loaded touring I think that is good, actually really good, I have seen Santana's and other top brand names with way more problems in less miles.
Now the bad....the frame on both is sort of like riding long piece of pasta...lots of twist, lots of give. The front wheel is an off brand which may of been the source for the wheel bearing and races giving out.
I just upgraded to a da Vinci and its great but it cost a little more (read lot more).
If I had not bought the KHS I would not be riding the da Vinci now, its hard to get any other tandem for the cost of the KHS. Its good to say buy a good used one it's hard to find something with modern type parts for the price of a KHS.
Overall the KHS has been great, it got us into tandem riding.
The only reason I upgraded was to get a coupled tandem.