atufano- thanks. I have been actively interviewing our local heating service guys about just that issue. The consensus seems to be that the MPO is better than the LE. It is also 100 lbs heavier.
The Buderus is very popular here. I have been looking at the G125BE which has the 89% AFUE to satisfy the bureaucrats for rebates etc. I don't see a 2104 on their website.
My problem is that I have 2 people right now ready for cheaper than Buderus boilers. I have to settle on a budget line. Something not as heavy as Wiel McLain Ultra at 630 lbs! I think the Triangle Tube must sit hot all the time, right?