Kim - the important thing for T2s, using a meter, is to recognise the trends you see when you test your bloods. Clearly, initially one is looking for a reducing trend, then once in a good place (hopefully!), one is looking for a steady state, as opposed to lots of very highs and/or lows. Flitting back and forth between the two meters, if they don't read too closely, isn't necessarily helpful, although one would expect to see the same trend of graph line of readings, one may just shadow the other higher or lower on the axis.
The actual number we see is less important, but I agree it can be unsettling when the two don't align.
Clearly it makes sense to use the meter you have been prescribed, as I am assuming you are also receiving your strips on a repeat prescription? There's no point having GP support and the paying good money to buy something different, because you might prefer the numbers.
Again, the trend is your friend.