Gunze Sangyo Hobby Color

Has anyone ever used Mr. Hobby "Hobby Color" to paint their Gunpla? I have used Tamiya acrylics in the past. I got this set of paints for my 1/100 Saviour. The guy at the local hobby shop told me that I did not need thinner on these paints. I don't believe him. Is that true? Can someone confirm this. Thanks