GT - The FR 35 is a good watch overall. Its main shortcoming is that it sometimes takes too long to link up to the satellite signal. Also, I have heard that watches with GLONASS capability are more accurate, and the 235 has this capability.
If I recall correctly, you do not have a smart phone. That may be a factor in getting a fast GPS lock. I think the Garmin Connect app will update the GPS almanac(satellite locations) for the watch via the bluetooth connection. I'm not sure about your particular watch, but you might be able to check this by going to the settings and finding the about info and then flipping through that to find the "EPO" status. If it says "current" you should be getting a relatively quick GPS lock. For that watch I would expect you to get a lock in less than 30secs with most of the time being much less than that. Waiting 30 sec. after getting an initial lock should improve accuracy since the "ephemeris" data should be received from the satellite within that time. If you have some device like smart phone, iPad, or Android tablet. Set it up with the Garmin Connect app and connect get your watch to sync with that. It is possible that the GPS almanac to get updated when you plug your watch into your computer, but I am not sure since I do not do that.
I'm not sure GLONASS really does improve accuracy. It might under some rare circumstances. I keep it turned off. I think the Forerunner 35 has GLONASS support.