Right guys, here's my honest opinion about TFR, having used it for the first time yesterday.
It gets the green top layer of algae off conservatory roofs with ease and also aids in the breakdown of lichen growth on polycarbonate roofs (only one I've tried it on so far). These still took quite a bit of scrubbing though, but nowhere near the normal amount with cold water.
It didn't help in removing the lichen from the White upvc struts though, I had to give these a lot of elbow grease still.
After scrubbing all the upvc like normal on the windows, I then applied TFR to the frames and gave them a good scrub without any further water. I noticed a very slight difference, but wasn't impressed as I thought it was supposed to get rid of the ageing effect and get the whites gleaming again. Nowhere near the kind of results you get from applying a cream cleaner.
So, is it worth using? In my opinion, the amount of time spend applying the chemicals and making sure you've thoroughly rinsed all the suds off afterwards, pretty much counterbalances the amount of extra time you'd spend scrubbing if you didn't use it. Maybe marginally quicker with TFR, with only a slightly better finish.
I think the finish I get from dipping my brush in a soap solution and using hot water, would be the same if not better.
I used a mix of approximately 1 part TFR to 4 parts water. Perhaps a stronger mix on the next one, to see if it cleans the upvc better.
The jury is still out on this one!