Is there a middle ground between the Lean Startup crowd who say you should never write any code at the beginning versus op's view of a fully functional product? I'm pursuing a working prototype but am constantly being told by both camps that I'm doing too much or too little. I don't think wireframes are going to cut it but I don't want to spend every spare hour I have on what others have already said is a lonely and…
A simple product has a simple MVP, so that's easier to get to. Whereas you might not be able to afford to build a more complex product even as an MVP, so you'll want to validate it some other way before starting.
A product with an obvious, unique value add can get away with a barebones, ugly MVP because the people who want it really need it's core functionality. But if you're trying to get people to move away from existing products to yours, you'll have to convince them to switch and exceed their already met expectations. That can mean you'll need a more complete product.
In both scenarios, if you don't think you can meet their expectations yet, you might be better off with a contact form rather than failing to meet their expectations. If you do go for a less-complete MVP, make sure what you have is clean and polished, and have an obvious roadmap. You could still get early-adopters, and the more risk-averse will know to come back later but keep an eye on you.