Manuals available online!
You can't get them on the US site, yet, but you can get specs for the whole Portable Grand series here: http://music.yamaha.com/products/categoryProducts.html?groupId=24
The manual for the YPG-625/525 is here: http://www2.yamaha.co.jp/manual/pdf/emi/english/port/dgx620_en_om.pdf
And for the YPG-225: http://www2.yamaha.co.jp/manual/pdf/emi/english/port/dgx220_en_om.pdf
All your questions can be answered here. The 225 has 3 Cool! and 5 Sweet! voices, but no Live! pianos and orchestra.