I bought my bass trombone from Laabs. It was shipped promptly and, as I recall, arrived in a couple of days. I had one minor problem with the horn and they expedited a new part to me overnight.
When you're buying Chinese stencil horns, a lot of what you're paying for is peace of mind. Higher price will generally get you more confidence in terms of warranty, customer service, and response. The best thing to do is to address and probe those issues with the vendor before you make the purchase, ask specific and pointed questions, and follow up if anything's not clear. If you don't get good and satisfying answers at that point, you're probably not going to get them after you buy. If you do get them, then you have a record to serve as a base for any future support.
Gary Merrill
Wessex EEb Bass tuba (DW 3XL or 2XL)
Mack Brass Compensating Euph (DE N106, Euph J, J9 euph)
Amati Oval Euph (DE 104, Euph J, J6 euph)
1924 Buescher 3-valve Eb tuba (with std US receiver), Kelly 25
Schiller American Heritage 7B clone bass trombone (DE LB K/K10/112/14 Lexan, Brass Ark MV50R)
1947 Olds "Standard" trombone (Olds #3)