Adams has a nice product line for sure!
Since it's a CPO, you have that 1 year cushion (if they haven't changed the policy) to figure things out. If the SHO drives well at all levels of throttle input, you'll probably be OK. The OEM brakes are pretty stout on the 13+, so stopping power should be pretty good. But the techs may have resurfaced the rotors/pads, so be a bit cautious on that score.
Might have an issue with a valve cover leak in cylinder 3 (driverside, firewall), or excessive precip in the PCV system (noticeable in the intake tubing/intercooler), or more rarely turbo oil feed line leaks. If temps get low where you are, might see that puff of "smoke" on startup from condensation, but that should be it. Should be NO smoke when you lift from heavy throttle.
As the reports of incidents continue to trickle in, I wouldn't be surprised if you had 1 or more hoses left loose by techs after a service visit. They can then work themselves completely off and effectively leave you without turbo power.
The rear turbo is a PITA to change out, you have to drop the subframe in that corner. Use quality & correct weight oil, quality oil filter to cut down on PCV and lubrication issues. At the very minimum, Motorcraft 5W30 + FL500s combo.
Batteries do get eaten for lunch, don't underestimate the importance, that's why I mentioned that. Is the mileage primarily shortdistance driving, was it weekender-type mileage, ...? Short trips will not charge the battery adequately, and you need to use a digital load tester to see if the CCA's still meet specs.
Check to see if there's any signs of rubbing on the paint in the trunklid area (when it's closed). Seems the bump stops can be inadequate to support the weight of the trunklid and it can contact the paint underneath.
The engine air and cabin air filters are likely to be filthy, so plan on changing those. Climate control should work properly, with heat and a/c coming on promptly. Check that you can direct the air as desired: floor/vent/defrost etc. No clicking from the dash either.
Does it have remote start? Read up on how it's supposed to work (online
owner's guide) and test it out. Make sure you get 2 original keys (with different entries in the PATS system) from the dealer. That's a minimum to add keys yourself later.
SHO Performance Package includes performance friction
brake pads, sport-calibrated steering, AdvanceTrac® electronic
stability control “Sport Mode” setting, 3.16:1 final drive ratio,
Alcantara® suede-trimmed steering wheel, 20" machined and
painted aluminum wheels with P245/45R20 Performance
Summer Tire Compound and tire sealant/inflation kit (n/a with
adaptive cruise control)
Note that the PP option deletes the spare, but you can fit a "deflated" fullsize spare in that space if you like.
And there is the possibility that you are getting a tuned car, so you will have to change out spark plugs very soon. Plus if the PCM calibration gets updated, it may not drive/shift like before because it will be "stock" again.
TSBs for the 13+
http://www.ecoboostperformanceforum.com/index.php/topic,3836.0.html
TSBs for the 10-12
http://www.ecoboostperformanceforum.com/index.php/topic,496.0.html