a window of opportunity has opened up for me to buy a new lens in the next weeks and i'm looking for some suggestions. it will be paired with my new 7d. i mostly just take pictures of my kids and friends. right now i have a nifty fifty and a 18-135 f/3.5-5.6. here's what i am thinking: i'm ok with the IQ of the 50mm 1.8 but really don't like the plastic construction so i originally thought of upgrading to the 1.4, but heard the micro-usm is problematic in the long run. i was also thinking of selling the 18-135 and trading up for the 24-105 f/4 L. but then i thought that instead of upgrading, i can get something new that covers what i don't have now. i'm leaning towards the 85mm 1.8 (but concerned that it might be too close on the 7d, esp. indoors) or maybe even the 60mm 2.8 (tho macro, apparently good for portraits, too). Was also thinking of going lower to 35mm, too but i've heard the AF was really loud for that one. any suggestions?