I have a number of Grizzly machines and happy to say no problems.
I have not looked at the Rikon machines. I recall a thread on another forum where a person ordered a Rikon bandsaw and did not like it so sent it back. Could be a one off.
There are a number of threads on the site where people have loved or hated a Grizzly machine.
So if you ask enough people you will get a variety of opinions.
If I were considering these two machines, I would give the edge to the Rikon, since I think a saw without a riser is going to be easier to tune and maintain than a saw with a riser. Just my $0.02.