They have never really done much for my hair. I wish they would, as I love the fact they last ages, are relatively inexpensive, and are multi-use and packaging-free; every so often I try again. My partially-used bars are great on the DCs' hair, though.
I use the purple one for travelling, it is stuck in the tin, but I just rub the open tin over my head and only start prising it out once it has worn right down - they last ages though. I use it for body wash as well. I'm never quite sure about what it does for my hair as we have very hard water and normally holiday in soft water areas which makes a difference. I still use normal conditioner.
The staff are very helpful and knowledgeable, just tell them what you want and they will find it for you, they are also very good at giving out free samples.
I use Ultimate Shine and I love it, the smell is lovely reminds me of my nan's old coal tar soap (not lovely to everyone I know) and it lathers well, really rich lather, leaves my hair squeaky clean and shiny as heck.
I use the purple one for my greasy fine hair and I really like it. It lathers really easily and leaves my hair really shiny, although that could also be the veganese conditioner I bought with it. I haven't travelled with it, but it doesn't seem to stick to the side of the bath too much. A bar seems to last ages as well, which makes it good value. You could buy online if you don't like the shop assistants? Expensive p&p though
The two I've tried both seemed to leave a film on my hair, it didn't feel like they rinsed out properly and left my hair a bit lank.
They are very light for travelling with though. To be honest I don't particularly like bars of soap and these had the same issue - they got totally cemented to the little container they were in and it was a faff trying to keep them out of the water in the shower so they didn't just dissolve. But that's just my prejudice against solid soap, if you like bars of soap these aren't any different in that respect.