There will always be people on both sides of the fence and designs vary as well. But in the Stock classes, most small block racers do not use a tray. Not sure about big blocks, but they are somewhat different with "skirted" blocks.

Personally, I use a double-sided scraper. I always felt that an OEM style tray can actually trap too much oil. For as long as I remember, I always heard that the "windows" in the trays need to be opened up. Basically bending open the flaps more for drainage. I believe screens are better than trays because of the drainage area, but scrapers actually "scrape" the oil from around the crank to keep it from staying wrapped around it. A properly designed scraper and tray/screen can offer the most oil control. But it gets complicated and expensive.

More info on scrapers here:

Crank scrapers