It's good to hear that the InRatio strips may have resolved an accuracy issue.
I've tested my blood using InRatio and InRatio 2, Coaguchek XS and XS Plus, ProTime Classic and Protime 3, and, most recently, Coag-Sense.
I decided years ago, after relying on my InRatio to give me an accurate INR value and paying the price when it didn't, that without some validation of a blood draw by a reliable lab, I couldn't trust either InRatio model. Although I had what may have been enough strips for a year of weekly testing, I decided to stop using the InRatio meters - my life was worth more than a box of strips.
My meter of choice is the Coag-Sense (somehow, over the years, I've wound up with three of them). I've switched medical providers and compare the Coag-Sense results to the lab. Almost consistently, the prothrombin times for meter and lab are practically identical. The INR reported by the meter is usually .2 - .4 lower than the lab. The difference is probably a result of the lab's reagent value being different from the one on the Coag-Sense strip.
In either case, the results are within the 30% acceptable margin of error recommended by ISO. I had also been testing with the CoaguChek XS, but don't use it very often. The results provided by the XS are usually higher than the blood draw. For me, I feel more comfortable with a meter that understates my INR than I am with one that is slightly higher than the lab's results. If my Coag-Sense gives me a 2.4, the lab usually says 2.6 - 2.8 - meaning that my INR is safe.
The company that makes the Coag-Sense recently upgraded its firmware - I don't think Roche has ever had a similar upgrade to the XS meters.
For me, although it's less well known, I would rather trust my life to the Coag-Sense than to the other meters.