That has very much been the main complaint with the original GP-1. Many reviews say it is slow to lock and doesn't at all in environments like wooded areas.
I ended up with the Solmeta Pro2. The GPS part works great. I got the Pro2 over the N3 because the Pro2 has its own battery. However, the Pro2 needs to have a disconnectable cable at the unit in order to charge the internal battery. I've already destroyed the connector once and it often gets knocked out. The N3 has no internal battery but the connection to the unit is permanent.