I completely agree Mel. My main hobby is woodworking. I have a 'shop full of woodworking machinery and so working with MDF is a 'known quantity'. Metal\Alu has never crept into my regular work and I've done very little with it, ever. It makes perfect sense to build from metal to maintain the highest amount of rigidity. But metal generally costs more (if you don't have contacts or experience) and is much harder to work with. Aluminium profile take away some of that complexity but for a price. Also, I can't help looking at all these '8020' builds and thinking it's a wast of good profile. It seems like 90% of that stuffs usefulness is not used. Having a profile which has four sides and up to 6 channels and generally you only put 2 bolts in each end. Maybe I'm wrong? Despite my comments, I'll probably go with alu profile on my second build because other types of metalworking is not something I can do. Thanks for your help on this but I think for my first one I'm going to stick with MDF. Although I might add some angle profile to some of the edges to firm them up.