Changing Meter type and consistency concerns

I have been using the Ultra Touch 2 BG monitor since Max was diagnosed.
I finally was able to purchase the Relion Ultima from Walmart over Christmas.

I used the Relion for the first time tonight and had a reading of 262. I immediately compared it to the Ultra 2 and had a reading of 318. Pretty big difference.

What is normal practice?
How often can I switch between the 2 meters?
I am worried about the different readings.

 

You can expect on average a 20% variance between meters. When I tried out a new meter and it was OTU for my new and true track as the old, I had really huge variances that made absolutely no sense whatsover.

I was told to pick one meter and stick with it.

I did find that my OTU 2 and OTU mini actually read within 2 point of each other. I returned the true track and never looked back. If you want to see what I'm talking about, look at the ss, I outlined it there.