Ran an Arrow GTR 21 for the first time today in my 8T 2.0, and I have to say it's an impressive mill, good balance of top and bottom end for our UK tracks (wide open, very fast) and a very smooth power delivery. I've run Alpha Plus for the last year, with the S852 'Orange' motor in truggy. The Arrow has about the same top end, a little less bottom but is slightly smoother to drive I would say.
Ran five qualies and a thirty minute final, only motor issue was it going rich when she finally broke in mid-Q4, but that was an easy fix. Other than that no flame outs or other quirks, and pretty good fuel millage for a new motor - running the 9mm venturi I think I could have just got 10 minutes. I opted to play it safe and settle for 3rd in the A-main on 8 minutes stops. Next weekend is our first national, so I'll drop to the the 8mm (possibly 7mm) venturi and start pushing the millage a bit.