To tell you the truth, I've only listened to two of their albums, but I think Verisäkeet is vastly superior to Kivenkantaja. So listen to the former; it only has five songs on it. Your life will be changed!
No the keyboards aren't like wintersun. They vary from simple atmosphere to being almost like another guitar at times, sounding more like a medieval-esque instrument usually... and they use some old instruments as well.