I've used WL developer for years and I think it's great, but it's not perfect. I also use Tradestation which has it's strengths (fast optimizations) and weaknesses (it's like pulling teeth to handle multiple positions). WL can easily handle multiple positions and can be automated, but WL Pro can only interact with Fidelity.
In short, I like it, many many others like it, while quite a few don't like it. It really depends what you want to do with it. For a newbie it can be good though, it has wizards to auto-generate code.