Richy,
Here are some results on some Tensid products I have used, but don't know what samples there are sending you.
Ezee Strip dwell time around 20-30 mins ok on concrete, stone and tarmac.
Graffiti Ghost, dwell time 10 mins again ok on the above.
Tavec 201 paint stripper, I didn't have much joy with this one as I needed to use on tarmac and not recommended for tarmac, plus the dwell time was to long for what I needed, as it would have trashed the tarmac, but it is supposed to be very good on other surface's.
If you have a look at there website, you used to be able to download spec sheets etc for each product they supply, so that might be worth doing to get an idea of dwell times and surfaces etc.