I have tank set at next to hotest which is about 140 I believe. Water once hot after a minute plus coming out of tub spigot is same temp as at tank. It is definately not an insulation problem as the old water heater worked perfectly for 18 years with same piping and insulation. We also never had a problem having a boiling hot tub with an 18 year old water heater. Even one or two showers now seems that the hot water out of spigots is not as hot as it was with old tank.
I am hoping it is one of the suggested problems mentioned in posts, Second anode, dip tube or heat trap.
The weird way the relief was set up on the old tank previously, no valve just a pipe that ended cinched two rooms away, literally just leaning on a piece of conduit next to the ceiling has me thinking maybe that had something to do with the problem.