MS2000 break quite easily.
The blue filter can come out of alignment the reed switch has a bad habit of breaking after frequent use and the battery housing wire breaks as well. Use good quality nicle cadmium batterys as your normal batterys can corrode easier and stuff it up as well.
The SDU series even though old hat are very robust, simple to operate and the only dramas I have had with them is that the rubber boot on the switch can tear around the base where it screws in.
Berfore you all jump in and tear this post to shreds, I have 15 years experience with this equipment, and though others rave about the MS2000 I don't agree with its great reputation.
Cheers all.