Yeah - I have decent quality locks at the moment and would only want to replace with equivalent, or use one of the ones that fits over the top. Manual override is also important!
As you imply, locks are generally false security anyway - if a thief wants to get in, most locks are trivial to pick, or bump, or you just bypass it altogether anyway (window/patio door/frame or brute force etc). My main concern would be being locked out legitimately rather than anything else, but then i'd only want a smart lock on the front door anyway so should be ok!
You are right though, have to be very careful as some...like the Yale one which does work with UK doors, are just terrible quality lock mechanisms. There is a reason that one is permanently on discount of 50% or more.