It sounds is if you are hearing Rolands sounds the same way that they strike me.

I have always approached the sounds of any arranger keyboard in the same way you would deal with a multi-track recording. That is to say that an instrument tone which sounds good when heard on it's own, may not sit happily in amongst the other instruments in a particular mix.

Equally the reverse can be true. A particular track or "instrument tone" may sound quite poor on it's own, but fits a particular mix just right.

For this reason, when looking at a new arranger with a view to purchase, I not only make a point of trying out a good selection of individual sounds on their own, but also seeing how certain key tones (i.e. the ones that tend to be most important to me) come across as part of the overall sound flavour of the keyboard.

As an example, there tends to be a fair bit of comment on Synthzones boards regarding the merit or otherwise of the basic grand piano sound available on each arranger model. My own experiences with mostly Korg and Roland stuff in recent years, suggests that both manufacturers piano tones are not very convincing when heard on their own, although they are very different from each other in character. However, I find the bright "up-front" piano sounds typical of the korg to be far more useful than the more mellow (dare I say muffled?) character of the Roland. The Korg piano sounds can cut through, when needed. The Roland's sounds just don't.

You're comment that Rolands samples may be more highly compressed is interesting. The "something missing" from the typical Roland tonality that I was trying to describe would fit with this possibility. It's rather like hearing a MP3 track versus a WAV file original.

A bit like the taste of cheese and onion flavour crisps (chips) compared with a really good lump of cheddar, together with a slice of hot spanish onion - if you see what I mean :-)