Been on a huge learning binge with ASP.MVC 2 lately, and recently uncovered there are different rendering engines out there... Spark especially caught my attention, couple of th
Depends what you want to do with ASP.NET MVC. We are in the middle of building a large enterprise app with it, and I find myself slightly wishing we used Spark. But this was only after about our 200th view was completed that I felt comfortable enough with the framework to consider snapping in something else.
I would recommend building some small apps with the regular view engine first, and if you find yourself struggling with "tag soup" step back and consider why. In many cases it just means you should have made a better ViewModel and mapped data, created an html helper, or utilized a partial file rather than filling your view with tag soup.
However, there are times when conditional and vast looping logic is required in the view, and this is when you might wish you had Spark. The nice thing is that you can use both side by side. So I'd say go with the default, and fool with it once you're comfortable.