Learn Me - 2010ish Hybrid Tahoe, Yukon, Escalade

I had an 05 Tahoe that I sold last year when I moved & didn’t have space to park it at the apartment complex I wound up at for a while. I really liked it, but the pre DOD versions are getting kinda long in the tooth. So, like the thread title says – what’s the deal with the 2010ish Chevy Tahoe, GMC Yukon & Cadillac Escalade hybrids? I see them up for sale occasionally with probably 50k -70 k fewer miles than similar non-hybrid models for the same money. Is there some major problem with them? Is it fear of the hybrid battery system going bad? Or are they just undervalued due to limited production and limited sales data to determine market value?

Any special issues to look out for?

Are programmers available to tune out the DOD function like regular GM LS motors?

I guess while I’m asking questions, what about Ford Expeditions? I have heard some rumblings about issues with the 5.4 motors once they get into the 200k+ mileage range. Is this something that can be handled as preventive maintenance for a reasonable cost before destroying the motor? The few people I know that have had issues with these have said they lost power and had a check engine light come on and when they took it to a mechanic they were told it was new motor time, so they replaced the vehicle.

It looks like Ford dropped the V-8 and switched to just the 3.5 Ecoboost in 2015 and the only ones in my planned price range are very high mileage which concerns me.  Any info on problem areas or necessary preventive maintenance for a high mile Ecoboost?

Thanks for any insights.

I had a 2008 Exped with the 5.4 from 40-173K miles before I sold it.  Bought it at a discount vs similar year Tahoes due to the percieved 5.4 issues.   If taken care of these motors last.  Key words are "if".  The 2007 and early MY 2008 motors could break off spark plugs but there's a known kit/fix for that.  Keep up with oil changes and go to a heavier weight 10W30-10W40 oil and these run well.   I know this causes arguments amoungst some folks but ford specs a higher weight oil outside the US where CAFE standards dictate a thinner oil.  

That said, a bad running 5.4 is something to run away from unless dirt cheap.  If its already running bad you're looking at new chains/phasers and if too far, the heads since the cams dont have bearings.