AO Smith Vertex Or Polaris Reliability/Reviews

d's

Hi gang,
I use a single tank for DHW/space heating(open direct slab with more loads coming) and am looking for a high efficiency condensing gas storage tank to replace the existing inefficient one which is on it's last legs. Wondering if any of you have experience with these types of tanks(such as Polaris, Vertex, Advantage Plus, EF Series, etc...) and can vouch for their reliability. I have searched this forum and there are only a few reviews, some negative. Best price I've seen so far is for the Vertex 100 on Pexsupply.com for $1950 US incl. shipping so am leaning that way but wanted to make sure I wasn't buying a lemon first.

Any advice most appreciated.

Should be an interesting system once completed as I'm also installing a roof mounted integrated solar preheat tank.

D'S