I have had 3 in the past…
2 mountain bikes and a road bike, which have all been great. I also got the handlebars, stem, seatpost and seatclamp with them all, and they work well as well.
I personally think there great for the money, and worth a try any day.
As for the income tax, i contacted the sales person directly instead of going though Ebay, that way i got them to put the parcels as gift, and lower the retail price of them down, so i didn't pay any import Duty/Tax.
Total cost for me including all the other bits was –
Mountain Bike – £270
Road Bike – £350 (That had a Road Fork with it as well)
Definitely worth a go…
Email me if you want any more info
Cheers
Josh