Hi,
Basically everything which has already been said.
I know you say its about 10 years old but is it the dark brown steel framed one, or does it have an aluminium frame.
A couple of pictures would be nice.
If its the steel frame I would hang onto it and not worry about what people think or if they are passing you.
Dawes were (and probably still are) quite a good mid range brand.
That style of bike with a steel frame is one of my favourites, being sensible you can ride light trails, tow paths, roads etc in a nice relatively upright position and take in the sites. A pair of cheap bar ends could help .
Racks and panniers should be easy to fit too.
I am slightly biased though being a lover of steel frames.
You'll need to spend a lot on a high end tourer. Just google to see what people tour on and do long day rides on, you might be surprised.
Not everyone spends hundreds, even if they can, on new bikes, although it can be addictive.
For what its worth one of my bikes is a 1988 steel framed MTB which I use for days out and I don't worry about the speed I'm toodling along at.
Just get out, ride and enjoy the bike for what it is.