I actually did better on the Letrozole than I did on the Tamoxifen so go figure? I ended up going off it because of a heart defect I had developed way back during chemo and apparently my heart needs some hormones to combat the fault.
My eyesight improved on Letrozole. The hot flushes were not quite as bad on the Letrozole. I had a bone density test and my results were that my bones were 15% better than for a person of my age.
Everyone is different. Just give it a go. If its not for you then there are alternatives.