Which one - Indirect Water heater - Bock or Heat-Flo

[NoEffort]

Just installed a new Weil Mclain WGO-04RD boiler and replacing a 26 yr old bock indirect water heater (no problems with it - replaced anode when needed).
Any recommendations on either of these.... Both same price installed.
Bock sidekick 40SK that has a glass lined tank and Heat-Flo HF-40 stainless steel lined tank.... both lifetime warranty.

 

[Fitter30]

Heat Flo because its stainless. Under maintenance in the install manual how to chemically clean the heater with ice machine cleaner and stress how often they want the anode rod checked. I'm sure if there is a warrantee claim first thing to deny is not following manual to a tee with either brand.