I've had a Magellan 9055-LM for about 2 years now.
The 1700 seems to be the same minus a few features like live traffic and bluetooth (both of which I have found completely useless.)
One of my biggest gripes with Magellan is their support for older products. About 8 months ago, my GPS suddenly slowed down, the voice was choppy, doing POI search would cause the GPS to reboot, entering addresses is slow to respond to key presses.
When I called support, they asked me to reboot about six times, no help. They then told me that a software update has caused this behavior and others are experiencing it as well. When I asked how I can revert to an old version, they said it couldn't be done. When I asked how to do a factory reset, they said it could also not be done. But they did promise that a new software update was coming soon and it would solve the problem.
Well, 3 months later, there was a software upgrade, and it did nothing for any of my issues.