LM? Unwieldy? It just looked like it.
"[...] but as the unwieldy lander fell further and further behind schedule [...]"
Yes, the Apollo Lunar Module certainly looked unwieldy. And yes, Grumman had a lot of trouble delivering a working version (manufacturing quality control issues, engine supplier issues, NASA demanding weight loss at a late stage largely due to LM design weight increases, and so on). But every account I've read of how the things actually handled is in line with Jim McDivitt's written comment to the designers: "Many thanks for the funny-looking spacecraft. It sure flies better than it looks" - after he'd got back from the first time of trying it out on the Apollo 9 mission. Pretty good going for a firm that had made its name specialising in robust propellor-driven naval fighter aircraft.
According to the Apollo 11 Haynes manual, "Everyone who lived with, worked with or flew the Lunar Modules fell in love with them."