A big downside to the Garmin 405 for me was the length of time it took to find and lock to a GPS signal. Often minutes before a run would be needed. I guess I should use the time to warm up but I use my run to warm up slowly to start with. There are plenty of studies that find warm ups for runners make no difference to if you will pick up an injury or not.. similarly people who go to the dentist every 6 months still need fillings now and again!
Good news is Garmin have fixed the problem with the 110 -- provided you start up in the same area you finished your last run in. Obviously it stores the last known lock and attempts these again first I guess. Locks on with 10 seconds here.