I still use the Olfa cutter I bought nearly 20 years ago. I have had no reason to replace it - it's not broken. I have a couple identical ones, too, given to me when a friend died.
Because I have taught quiltmaking for so long, I have tried just about every cutter out there, but I still end up with my Olfa. If I ever do need to buy a new one, it will be the Olfa retractable. That is the one I recommend to all my students.
If it is skipping threads or not cutting well, the problem is the blade. They do need to be changed more often than you might think.