I used to always also this question with YashicaMat TLR (a great camera, by all accounts). But now that prices have gotten so low, I've started saying a Bronica SQ-A with a 80mm lens and a waist level finder is a better entry point. It is easier to focus than any TLR for those of us with (slightly) dimming eyes and can be expanded as far as you might ever want to go. The main thing is that any step to MF, in my opinion, should include composing on ground glass. The world just looks more interesting there.