The search functions on the new platform are nowhere near adequate - the admins have been made aware of that and were assured that improvements are coming. Aside from that, the new platform is light years ahead of old one for speed, functionality and reliability. Give it a chance.
I will give it a chance, but the efficiency of a good search far outweighs a slightly slower system response for me.
I will admit to being "old school" in the sense that I don't live my life on the web, but my entire laboratory career has been compute-aided, and no advanced search feels like going back to Fortran and punch cards.
Not being able to search a specific forum is very big usability issue, as often only want to search the sub-forum for my generation Odyssey, and don't want or need to see posts for newer/older generations.