Vision Ego V3 Clearomisers - Request for Maintenance/Use Tips, Expected 'Lifespan'

[dpower7]

Info sheet accompanying my starter kit states "They can be refilled many times before the atomiser head requires replacing". Would really like to have a better idea as to when I should replace the atty than when I start getting a nasty burnt out taste - which is what I've read in posts as the definitive indicator. Also even if always refilling with the same type eliquid, is it advisable to occasionally clean out the clearomiser (every third/fourth time, when replacing the atty,...)? and what about the wick? (does it need replacing) - or considering the relatively low cost - just easier to replace the whole thing after n number of atty replacements? Thanks for any/all replies.