I'd take the 300 over the R22 any day. The 22 is nice on a cross country with that bit of extra speed but that sit in my books. Was in a 300C last week hovering at 5000 MSL, 55 degrees F. In my books that gives a DA of around 10000. Pretty good going!!
Ok, either it was 55° C. up there or you were about 5,900' DA...
check out the online E6B