Reliability
 

My wife and I are considering a 2014 S550. Would like to know if this year model is reliable to date?

Welcome to the site! A suggestion is to post the question in the S-Class specific forum. I will likely get more views from people who are knowledgeable.

You could always check consumer reports, and it always depends on the vehicle history, if the owner(s) took care of the car an got it regularly serviced and fixed the possible known problems (as there are with most chassis) then it should be reliable. Tbh I'm more of a youngtimer Mercedes guy, but if you want the newer stuff. I'd choose wisely.

You can also check on KBB.com for ratings and reviews.