When it first came out, I compared Doom3 to HL2 and saw an inferior engine. 1 was a revolutionary jump (d3), the other an evolution of a previous engine (hl2). Now you are stating the same thing I stated way back then, except 4 years later, which means your viewpoint is so very far from new. What I learned from HL2 was, despite the evolutionary nature of the engine, Valve has managed a very consistent roll out of extremely high end content. Over the course of it all, the engine has aged nicely and I've begun to overlook a lack of fancy effects. TF2 makes exceptional use of the Source engine and I can run it at 2560x1600 res, something I can't say for Crysis.
Outside of graphics, the rest of your post/argument seems to be full of complete factual inaccuracies. The crux of your post seemed to be "same enemies, same puzzles", more of the same, etc. The problem with this, is it's just not true and makes for a pretty shitty "review". Valve has been very consistent on adding new content. Episode2 focused on some pretty decent outdoor areas, nothing on Crysis, but big enough to be enjoyable and allowed them to create the sticky bomb puzzle, which was brand new in EP2, the grub section/enemies were brand new as well, and so was the new striders, we got a sneak peak at the brain bugs which will most likely make more appearances later on.