Thanks everyone. I feel mucho better now

But, last night I was definitely going to send it back. I did the OS update and then factory reset (as suggested and also did it on my 16GB). Then started making some changes in the system settings and just generally looking around. The entire system had a lag like I've never experienced. When I got the 16GB version I never had the dreaded lag that everyone spoke of. Now nearly all the windows are taking 3-4 seconds to open :o This must be what everyone is complaining about and it's SO not acceptable! I restarted the tablet to see if that helped. It didn't. OK, it's going back

Turned it OFF. When I got up this morning I turned it back on and, so far, everything is back to it's (semi)snappy self. I wonder what turning it off for several hours did that a restart didn't do?