Spark plugs should be replaced as part of routine maintenance.
Spark plug to the engine: 22-23 Nm
Bosch +4 Platinum
There are tons of threads on this subject, half of the people who never owned +4 platinum/had other issued with their car seem to dislike them. People who actually used them seem to enjoy them. Personally, I have not experienced any issues with these spark plugs and would recommend them.