It is a good deal also considering higher J&L prices this year.
They did change the impeller not recently but some time ago.
The old one was Milty part design unit that would get stuck when calcium overgrows it.
old you can disassemble
http://www.tunze.com/fileadmin/image...e/6100.600.jpg
new can not take apart
http://www.tunze.com/fileadmin/image...e/6100.700.jpg