Although I've used it only once, I was also very pleased with the results after applying Leatherique. Much, much better results than some other products I've used! However, like you, I also found it to be a little inconvenient and time consuming to wait the better part of a day to get the desired results. Nevertheless, given the result, I plan to now use it twice a year.
My '89 MB 560SL is a sunny-day driver only. It's not a daily driver. In addition, although it's almost 25 years old, except for feeling a little hard and dry prior to the treatment, the leather was already in very good condition so, to me, given the smooth, soft, clean feel of the seats, etc. following the Leatherique treatment, the little time investment twice a year seems worth the trouble.
Just a question...Unless you're really hard on your leather, or it gets so dirty that you feel compelled to clean and treat it each month, wouldn't it be just as easy to increase your Leatherique treatment to 2X yearly (e.g.Spring and Fall), and get the fantastic result from a product with which you're already familiar, and from which you're already getting really good results?