You'll probably get several answers both pro and con. Mine is con, my 200 is still running more as a display than a functional data collector, I plugged the old 100 back in for that purpose. Some guys seem to be having good luck, overall I'd have to say that's more a testimony to Oregon Scientific's quality control, or lack of, than the device itself.
Once you download, the data logger it empty, so depending on why it wasn't a good download it the data is probably gone. I've found that if I let the 200 run stand alone and then at some point download to VWS it works, if it's hooked to the pc 24/7 it corrupts data. Someone with WD can better talk about the download there.
Part of my problem was a bad temp/hum sensor with fleawatt transmitting range, using other sensors has improved the situation dramatically, again a QC problem, several guys are having good luck with the same sensor.
If you want higher quality, go to Davis, but you will definitely pay a higher price.