In my view there is no need to sacrifice whichever brand. On the Dutch keyboard forum I have posted a lenghty article on the merits of having two brands at your disposal. In essence my point of view is that most folks will be better off with both a Korg and Yamaha than with only one brand of keyboard. ( please subsitute either if you like by Roland)
If you are on the smallest possible budget a PA50 ( or Micro) combined with a Yamaha PSR 1500/3000/700/900 will cost you just over 1000-1200 euros. If you have no financial worries go for the PA3X and the Tyros 4.
Mind you that will set you back approx. 7000 euros, at least overhere in Europe. In between are many other options. Being a Korg man myself I have grown quite attached to my recently acquired PSR900. I amplify the Yamaha via the Korg PA800 which gives it an additional boost. I was lucky to acquire the used Yamaha for only 700 euros. All in all my set up cost me considerably less than a plain new Korg PA3X (without the speakers).
Don't get me wrong, I ain't knocking the PA3X or the Tyros 4 for that matter, all I am saying is that in my view it is often best to go for two brands of keyboards, even if it entails " having to make do " with the sub top or dated top model.......
Just my 2 cents.

regards,
John Smies

P.S. I am glad that more and more folks are beginning to discover the potential of the Micro in whatever set up. I wish my Yamaha PSR900 was a micro version. As it is it takes up rather a hell of space............ smile