Looking at an 01 ob with the 6 cylinder. Will that be more reliable than the ej25 that just blew the gaskets?

as long as it has not been over heated,

yes!!!!!

They are reliable, but front end parts seem to wear faster because of the heavier engine.

excellent engines - make sure it doesn't have headgasket issues - these things are a beast when the headgaskets fail in them.  it is "thought" that they have fewer headgasket issues but enough people have had HG issues in the H6 that you want to be careful for sure.  it's twice as expensive to repair as the 4 cylinder headgasket to repair due to the significant chain cover labor.

 

check for external seepage at HG seem under engine and look for bubbles in overflow tank while driving, after spirited driving/uphill acceleration, while hot, or immediately after shutting off.  any small bubbles in the overflow tank and you might want to avoid it.