I had used MU for 2 years and while I liked it ok (I only gave it 3 of 5 stars) I found $100.00 for a 5 year license a bit steep. Only kidding, 'tis but $20.00 for a 1 year license.
Still, because it was better than the rest, I used it. Then, when it was time to renew my license, there were great problems, none of which the developers were able to resolve. Ergo, I am now sans MU and I still don't know if my credit card is put to right…
Fortunately, many developers include the option/preferences to auto-notify or download when a new version/updater is released. So that, with the potential of the App Store, and $20.00 in my purse, combined with my daily surfing habits, muchly negate the need for MU.