i have the sigma 70-200 f2.8 ex dg (no macro).. love it.. kinda soft at f2.8 so i usually shoot at f3.2 - f4 in the day, at which it's reali sharp.. i only use f2.8 if i reali need it (eg. soccer games at night) but the results are still very acceptable..
u can check out my shots using this lens here.. the carpark rally shots and the soccer games are mainly with the sigma..