The de-lamination was always an issue with my ABS parts. Maybe I just sucked at printing with ABS.

They mention on their website "all metal hot end heats up to 300°C". ABS melts at around 200 C. That hot end screws into a metal part, probably aluminium part. That aluminium part is sandwiched between 2 ABS parts

If I where you I would send them my biggest STL file, tell them you will pay them for the part and ask them to print that while recording the print. $2000 or $3000 is alot of money to be unhappy with. Do you have reviews from other users of the printer that have printed the size of things you want to print?

Another option is go to https://groups.google.com/forum/?fro...makerbot-users and find Jetguy. He is a god when it comes to printing. Ask him what he things about the printer.
Seems TobyCWood has also used the Taz 5 https://groups.google.com/forum/?fromgroups=#!searchin/makerbot-users/taz$205/makerbot-users/dYs-4QHKbyU/hRTWlltpfo8J

I hope others can also answer your questions about the Taz 5.