ok so this is my collection of lenses all minolta

35-70 f3.5-4.5 which i LOVE
35-70 f4 which i got for the macro capability-pretty cool but not as sharp as the one above wide open
50mm f1.7
70-210 f3.5-4.5 which i LOVe also

i was looking at the tamron 28-75mm f2.8 would that be a good addition to my collection? since its faster than my 35-70 and i exclusively photograph my son so i only do portraits. seems to get pretty good reviews, especially for the price..i do like sharp images, but corner shaprness doesnt bother me as i dont do landscapes. just wondering if anyone has one and what they think of it..