Hi Sushil,
Basically there is no difference: the one embedded into Collect is the community edition of Saiku server version 2.6. We removed the admin console to reduce the size of the package and because it's not needed when using Saiku inside Collect.
The beta name refers to the way we generate the Mondrian schema used by Saiku. The Mondrian schema is generated starting from the survey design but it's bot perfect yet (there are some cases of complex surveys with nested entities where the generation of the schema fails) but we are working on it and we'll remove the "beta" from the link when it will be (almost) pwrfect!
Thanks,
Open Foris Team