I was not suggesting to download the manual of a keyboard,so that you would choose basing yourself on the manual. I meant that you download all the manuals of both keyboards,and compare the features. Compare the demos,everything. Just compare what you can.
You should try both boards if you can,but sometimes you can't. As I live in the UK and I can find an E-50 for £ 588 and a Yamaha psr-1500 for £ 750,I would have no particular reason to choose the Yamaha. (after hearing them both on demo) Then again,of course it's only a preference,and of course you should try both if you can.
The touchscreen on the Roland seems far more intuitive to me.
I just happen to prefer Roland for sounds. True,you get less poliphony (64 notes) but by all means that's not small...I had a Roland xp-80 had 64 notes of poliphony,a fully fledged synthethyzer(superior to arranger keyboards,-in matter of synth sounds and sound editing,not superior to everything-),and I assure you that I used to do quite a bit of sequencing,build complex synth sounds (multilayering etc) and i never runned out of polyphony. You could say that 64 notes of poliphony is fairly safe,they will not be taken up by a few tracks on the sequencer. Then again the Yamaha is excellent too,I am sure it's no piece of crap