+12 was there from the start. Again we're kind of puzzled why +12/+16 doesn't appear to be used in Australia.
An easier plane to fly is always a plus, and being able to escape at will is a very nice option to have, but in these mock combats it doesn't appear that the Spitfire--unlike the Kittyhawk--ever needed to escape.
Well that is just turn and burn vs. boom and zoom, just like when a P-40 would be fighting a Zero, the BnZ plane usually has an edge though certainly not always, and it depends by how much of a speed / dive advantage it had. But this does say pretty definitively that a P-40E could out-dive the Spit V, at least at the boost ratings they were using and with the Vokes filter. At +12 I don't know, though we don't know if the P-40E was using high boost settings either...
The 109F had a notable dive advantage on the Spitfire V.
The report language is a bit ambiguous but it sounds to me like they were saying in combats 2 and 3 that the P-40 was getting on the tail of / or making attacks against the Spit. Unclear if that means a "firing solution" but it sounds like it does. Combat 1 was 'practically' a stalemate with the P-40 able to make hit and run attacks. Combat 4 up at 20,000 ft clearly went to the Spit.
If this was the results of a Spit V (Trop) vs. P-40E, i.e. roughly even overall up to 16,0000 ft, with a speed advantage to the P-40, presumably this is how the other P-40 variants used in the Med should shape up:
P-40E - Takeoff power 1,240 hp @ 45" Hg, WEP 1,470 hp - power / weight 0.14 at military, 0.17 at WEP (sea level) critical altitude ~ 12,000 ft
P-40K - Takeoff power 1,325 hp @ 51" Hg, WEP 1,550 hp - power / weight 0.16 at military, 0.18 at WEP (sea level) critical altitude ~ 12,000 ft
P-40M - Takeoff power 1,200 hp @ 45" Hg WEP 1,300 hp - power / weight 0.13 at military, 0.15 at WEP (~8,000 ft) critical altitude ~ 16,000 ft
P-40F - Takeoff power 1,300 hp @ 50" Hg, WEP 1,435 hp - power / weight 0.15 at military, 0.16 at WEP (at 11,800 ft and 18,500 ft*) critical altitude ~ 20,000 ft
P-40L** - Takeoff power 1,300 hp @ 50" Hg, WEP 1435 hp - power / weight 0.16 at military, 0.17 at WEP (at 11,800 ft and 18,500 ft) critical altitude ~ 20,000 ft (maybe a bit more)
P-40K should be substantially better than the P-40E against the Spitfire particularly at low altitude (say below 3,000 ft)
P-40M should be similar to the E but equal to the Spit up to a little bit higher altitude, maybe 18,000 ft
P-40F should be a bit better at all altitudes up to maybe 22,000 ft
P-40L** should be substantially better up to ~22,000 ft
All versions should be able to out turn and out roll the Bf 109F or G up to their critical altitude.
P-40N's were also used in the Med in Italy and the Balkans, by the British, but I think almost exclusively for fighter-bomber sorties so I didn't include it.
* I have to admit I don't understand precisely where the Merlin 28 / XX reaches it's two highest power output points, one source said 6,000' for low gear so maybe SR8 can clear that up
** This would also be the same for field stripped, 4 gun P-40Fs