40 hours/week?
I'm not so sure they will last that long, but they do last a while. Lasting longer is certainly a great feature to have in a tip, but I would think that the quality of hit is the primary concern.
There are players that get kind of caught up in the cost of a tip and how long it will last, as opposed to how will it add confidence to one's game because of the quality of hit experienced.
But, the bottom line is, how often do you play? What caliber player are you? Are you able to detect a difference in the way different tips feel when you hit them? Does the tip compliment your game? Etc., etc. There are a bunch of questions that need to be answered in order for you to be assisted in making a decision.
Finally, I do agree with the playability and longevity of the Sniper tips mentioned previously. It seems that many, many players that aren't sure about what tip to have installed, seem to have no problem getting used to and liking the Sniper tip. Just one consideration out of many. Hope that helps.
Gene