Thats a neat link Fariz- that guy says the La-7 and La-5 had lower wingloading than a Spit IX though, which would mean they would out-turn a Spit IX . I'll have to look in my Spitfire book to see what the stats are in it and if they match up with this fellows website.
Ok, think I figured out the 'discrepency" - The "weight full" category corresponds roughly to the 'max overload' weight of the Spit IX, which is 9500 pounds (I assume this would be with a huge ferry tank or something), but max 'permissible' is 7,500 pounds and normal 'take-off' weight is 7,181.5 pounds. I know it is ~2.2 kg/ lb, so that'd be roughly 3,265 Kg instead of the 4,309 Kg listed for the Spit IXs weight.
Of course, the weight listed for the La-7 might be its max overload weight to, but I don't think it is.