I don't use clothing size as a guide ever! Have you read about vanity sizing? A size 4 misses in JCPenney's is a 6 or 8 somewhere else for example.
As far as the charts go, I hate to say it, but now that I'm closer to the weight I'm supposed to be I'm starting to think that they were right in my case. I can't say in general because 150 pounds might look good on a certain body type and you can't even tell they are over the charts while on some other person of the same height 150 pounds might look overweight. I say that as long as your cholesterol levels, sugar levels, etc. are okay and you're not currently suffering from joint problems, high blood pressure, or anything like that and you're happy with your weight then leave it alone.
Since we're sharing numbers (I would've never done this last year) I'm going to share mine. I'm almost 5' 5" and I on Sunday I weighed 142 (almost 3 pounds lighter than at the beginning of January). Although a nurse told me that if I wanted to I could stay at 145 I don't want to. I want to be 135 in a couple of months and my goal weight is 125, but that is going to take a long time because I'm losing about 2-3 pounds a month now. Last year when I had way more weight to lose I lost it quick, but now it's very hard. My main reason for having that goal weight is my joints. Since I carry my weight mostly in my lower body and I love my cardio I know that at my goal weight my joints are going to take less impact. I've noticed less joint pain as I'm losing more weight. My doctor told me to take a glucosamine supplement and I'm doing that with great results. He also said that 10lbs less are going to help a lot. I don't *need* to lose them for my health, but if I want to keep exercising (and I do) then he said it was going to be helpful. Another reason is that I want to be able to do more upper body exercises like push-ups, pull-ups, etc. that depend not only on my upper body strength, but my own bodyweight. As my upper body gets stronger and I'm reaching my goal weight I know those are going to be easier. Right now I can do about 20 push-ups on my toes and 1 unassisted pull up and I would like to do more than that in the future.
Everybody has their own reasons for paying attention to the charts or ignore them. Do whatever makes you happy as long as you're healthy. Take care.