Every non-summer SB suit I order these days is a three piece. I think i have just under ten. I love them so much I'm thinking about doing making some of my summer orders three-piece, which would allow them to be worn for a month or so before and after the hot season or during chilly nights.
I have several from Isaia and Ralph Lauren Purple Label and they are among my favorites. Today I was lucky enough to see a friend's latest bespoke creation which features a sweeping shawl lapelled double breasted vest that might be the coolest single article of clothing that I've ever seen.