I have gone between 14k, 18k WG and PLAT. Honestly I never notice a difference, but I'm also not color sensative which I think bothers most people. In regards to weight I also never really noticed a difference but I went from a heavy 14k setting to a light and delicate PLAT setting. Still I think it would be a small difference.
I'm with Sarah - I have several rings with different metals. My favorite **happens** to be a platinum ring, but I think that's because its just about the sturdiest I have without being clunky. I feel no difference between the 14k, 18k, and platinum, other than with the 18K, I feel like I could possibly bang and dent it - don't feel that way about either of the other two. So no, it probably wouldn't bother me either.
I can't answered your question cause I never had a platinum ring but for me, the best between 10, 14 and 18 kt is 18 because it stay beautiful long long way.
I went from an 18kt to 14kt back to 18kt. I'm very much a "my wedding band and ering metals have to match) and my wedding band is 18kt so I won't go back to 14kt unless it's a temp setting which we might have to do soon. But I did notice, the 14kt tends to stay silver color longer and it's a lot harder than the 18kt. The 18kt is clearly softer and it gets scratches easily.
My RHRs are 14K and my wedding set is platinum. For a ring that I wear daily I prefer platinum because it does not need replating and I think it wears better. However, many people have wedding sets that are 14K and they are just fine. Personally, I prefer platinum for my wedding set.