I have been told that rubidium frequency standards are hard to maintain. Is it true of the type shown here?
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=290286908728
These show a better stability than the other 10MHz oscillators in ebay at this time. Will they maintain their rated stability with no maintenance? What is your experience with these devices?