Thanks for all your replies, we have used a portable system now for a couple of years, and to be honest although it is very easy to align the dish & receive a signal, we find it is just another chore to do when arriving & leaving site, and with being a 54cm dish + tripod, cable etc, and even with it's own carrying holdall takes up a fair bit of room when in transit in the van, so we have opted for the fixed version, and if we get stuck for a signal we can always fall back on to the 530 aerial. I think the real truth is as we are getting older we want things that bit easier (lazy b*gers) so up for sale soon will be a 54cm dish + tripod + a 66cm dish for use further south and all cables.
Allan & Gill.