The LX200's are/were the top of the line. According to the Meade cataldog, the LX10/LX50/LX90's are all built with 'cheaper' bits. eg; gears = aluminium not bronze, DEC bearings = nylon bushes, lighter forks, Electronics, etc etc. Depends on the model you buy as to what/where they save costs.
The optics, AFAIK, are all the same tho.
All excellent t'scopes.
L.