Thank you all.
I have been dabbling around a little this morning with the demo version and indeed Rebelle comes a lot closer to 'the real thing' than the paint material implementations of PSP X7.
I particularily liked the dynamics, with pigment in watery colours actually setting in the lower edge of the painted area and dripping/sagging effects taking place.
Mixing of colours needs to be done on the palet. Wet over wet strokes with different colours do not mix well on the canvas, which is good to prevent a drabby mess like yours truly tends to make of his RL media. LOL!
Anyway I like the concise interface. You easily find what you are looking for.
Missing (or not found yet) is the option to have the palet as a separate canvas to pick color from (palet usually becomes a painting by itself), and to have different brushes loaded with different colors etc. available. (I tend to end up keeping 4 or 5 of those stuck between the fingers of my palet hand in a sort of 'fan'.).
In short: I am convinced. Need to save a little to get the $$.