One added bonus for me....I can now use FS Global Real Weather to inject weather into XP, something I couldn't do with SMP 4 as it killed my frame rates. So, another paid software I can use now! And at 30,000 draw radius as opposed to 10,000 draw radius. Take a look at the frame rates
Although, I was getting pretty nice weather/cloud depiction with SMP 4 and RWC also