Roger Cicala of LensRentals
has posted a partial teardown of the Tamron 15-30mm f/2.8 Di VC USD lens
His takeaway? Tamron's latest wide-angle zoom is well built but isn't nearly as modular as most of Canon's newest lenses; fixing one at home is not necessarily recommended because of the complex nature of the lens's construction.
Check out the LensRentals Blog
for the well-illustrated (and equally entertaining) partial teardown. B&H
carries the Tamron SP 15-30mm f/2.8 Di VC USD Lens