Hi Rob,
I too have been looking for a long long time for a decent portfolio component/extension. I must admit, up until now, I haven't found any that i find good enough.
They all have downsides for me. Some have too much information fields, where I just want to show a picture and title. Others don't show the pictures in a way I want.
Basically I think still the best way is a category blog and show a thumbnail and enlargement and next to it the information you want to show.
I think I previously gave you this link:
http://www.joomladsign.com/joomla-websites/
A category blog showing all items in alphabetic order. A few tweaks here and there for showing the info I want to show and an implementation of the HighSlide images. (
http://highslide.com/) I just love HighSlide
In short, I chose a work-around in stead of a component/extension. There might be some good portfolio extensions available, I just haven't found the one that worked for me.