Yes, light is better if you want to use the watch 24/7. I have a heavy stainless steel dive watch and it sucks to wear after a while. This is why I went aluminum. I dont see any Apple Watch as a statement of style like a classic watch. I definitely believe they can look very cool, especially with different band options, but the #1 goal of a smart watch for me is sleekness and comfort. Main point is that I looked at the weight of each model and 10+ grams is definitely noticeable when on your wrist all day.
For perspective, an aluminum watch is on average under 40 total grams. That is incredible, you should barely notice it. A SS is at least 10 grams more. It will still be very wearable, but weight is a major luxury when you wear something on your wrist all day.
A sterling silver large dive watch can weigh over 150 grams. After 8 hours, I usually am looking forward to removing it.