I have gotten a lot of good use out of entry level Garmin Nuvis. What i haven't gotten is long life. Typically i get maybe 2-3 years out of one before either the slider switch on the top fails or the USB connector fails. These failures are generally out of warranty and the only thing Garmin offers is an exchange for a refurb unit that is close to the cost of a new unit.
I don't recommend paying for lifetime maps on Nuvis. The lifetime of a well used Nuvi is simply not that long.
Having said that, i will probably replace the current Nuvi (failed slider switch) with another Garmin when the time comes, but i may consider going a little upmarket next time out.