What is the legal structure of your business?

Is your product mission critical? Do you have to manage stock / ins and outs of cashflow? Do you want to serve enterprise clients?

Now and again there are reasons to have an LTD e.g. if you want to get a contract with public sector, sometimes they ask for company records stretching back a few years. There are a bunch more cases like this where it's good to have an LTD but 95% the time you can probably get away without, and then if needed cross that bridge when it comes to it.

If you're in the UK like me you can register an LTD very quickly.