Massive Scooby fan here and we are currently on our third. Love them to bits as they are fast, practical, reliable and cheap to run. What we like about them is they are a solid work horse but also fun with a bit of character. Sooner be driving a Scooby than an Audi//BMW even if the quality is not as high.
It really does depend on what you are looking for in a car. If it's to do a lot of miles or just getting fed up with the race car feel of the DC5 then it will be a good alernative as it will still be fun, fast but not as focussed and more comfortable. They also do an XT which has the 2.5 Impreza engine and goes like stink still. Not an STi though
I've not driven an STi Forester but do hear great things about them. I think it will be a blast but not sure I would replace my DC5 with one. We would consider one in around five years to replace the Impreza as the kids will be older and that extra space and practicality would be nice.
This is our Impreza WRX.