There are several here who first saw ROTJ before ESB, and it seems like a really strange jump. You go from seeing Han being applauded in Star Wars to "we need to rescue him from carbonite!" in Jedi. Though upon second thought, we already know that Jabba wants him dead, so it's not really that confusing. The biggest thing would be the "I am your father", which is a really strange thing to have happen off screen. Though the series started with Episode 4, so it may have been an interesting experiment to continually skip episodes.

In fact, there's not that much which has been missed. All that happens in Empire which is important in ROTJ is the introduction of Yoda and Luke's training, Luke considering that Vader could be his father, and that's it. Even Han's belief that Leia loves Luke is more understandable without the intervening installment, as well as Yoda's insistence that Luke confront Vader, as if Luke hasn't done that yet. Lando's arc contributes little to the overall story, and it may even be more understandable that ROTJ Lando, who seems to know Han and rescued him from captivity, is now a general, rather than ESB Lando, who previously betrayed a leader of the rebellion. An interesting thought experiment indeed.