Personally, going pro is completely worth it from my perspective. The listening vector alone was already quite useful and the recent addition of the sentence quizzing is also something that at least I really appreciate.
Kise - if you haven't already, you will get a message through renshuu 2 days after you register with a free trial to use renshuu pro (no auto-renewal or any junk like that, just a simple trial) - definitely check that out when it comes in :)
