I just completed all of HSK 4 and 4+ Flexi classes on LTL. 100 classes total, I did them all in about 3.5 months, basically a class a day almost every day. It was somewhat review, as I have already taken and passed the HSK 4, but I wanted some extra speaking practice with limited new vocab. I'd say LTL runs a little harder than the HSK levels though, and I ended up adding at least 400 words to my SRS from those classes. I left a lot of words on the table for later as well. It was good speaking and listening practice with many different teachers, some I liked a lot and a few I didn't care for. Buying 100 classes comes out to exactly 8 usd per 1hr class, and you have six months to use the credits. Pretty hard to beat the price. The pdfs that accompany each lesson are excellent and do not really really follow the HSK format too closely. Lots of lessons on technology , "modern" and interesting topics. The "Free Speaking" classes need to be re-worked in my opinion though. Overall it was well worth it. Now, as I start working on HSK 5, I will go it on my own for a while and may do the LTL HSK 5/5+ flexi classes down the road.