The i-Tech is not seamless. It has a airweld down the side of the body. I saw your post on the ATB forum and yes the new ATB's are nice but they are over $200 more than a i-Tech.
I waited over 6 months for some more ATB Smalls to be produced ($950) and I finally broke down and ordered the i-Tech 100 with a Tunze pump at $452 and glad I did. Two months later and there are still no ATB Smalls available.
I think for the price, build quality, customer service, quality of pump, and ease of use, and performance the i-Tech is hard to beat. The new ATB's are sweet but so is $200 worth of frags + a new i-Tech that performs wonderfully.
It will be interesting to see what skimmer you pick.
How did your sump break?