I've been using Virosol 50% - 50% for the last 5 yrs on new cleans without having any problems but as others have said - don't let it dry 'cos its a bugger to get off. Heavy rinsing after application is needed but it will still 'bleed' out of the seals even after 3 or 4 big rinses. On a more positive note when heavily diluted by the rinsing the slight 'oily effect' (think engine oil rainbow in a puddle) left on the glass dries clear.
Only time I've had an issue with the orange crud which seems to be the staining people worry about was on a 'new build' fake roman column porch type thing (fibre - glass I think) few orange spots because I left it to dwell for too long in the summer. Re-applied loads of Virosol to remove the orange spots . Well most of them anyway!! Oopps1