I suggest you try it out for you and your company. No, I'm not saying java > perl or struts > mason. Every tool has its uses. It doesn't mean every tool should be used.

I'm a huge MVC biggot... and struts and mason both allow for this on some level. BUT there's a big issue. In both, you can embed code within your templates (jsp, mason's internal language). I'm a big fan of stxx which runs on struts. You send XML packets back from your servlets to the configuration engine and the engine is configured either to send XSLT back with the XML or apply the XSLT to the XML on the server side. So I hate struts AND mason. But opinions are like.. uh.. potatoes. Everyone has one.

I can't use stxx at work right now since I'm the only one who knows java in my tiny development group. The other guy is a perl/php head. I've setup a bunch of MVC-like tools and examples, and we have a standard of doing the same things. It's what's feasible.

So you see, it's not a matter what is better. You can measure the amount of instructions wasted, which would be marginal between the two systems, but it won't matter, 'cause they are both damned fast. It's like buying a car. You don't buy an expensive sports car 'cause it's fast, you can't fit in it nor aford to garage it, eh? Well, don't use a system that would be infeasible to use techically or socially. Doesn't mean you can't try it out though. :)