They ruined the neuralyzer gag....

I thought it was pretty clever that when they were going to erase J's memory when he first got back to 1969 that the he had to be placed inside a huge neuralyzer the size of a whole room. As we know, everything gets smaller as technology advances: the first computer filled up a room, early microwaves were the size of a refrigerator, early cell phones were the size of a large brick, etc. It only made sense that the early generation neuralyzers were massive.

But then near the end when they are at Cape Canaveral, it turns out that 1969 K does have a hand-held mini neuralyzer after all- it just has to be hooked up to a battery pack. Ummmmm, so why didn't he just use that on J in the first place? Why do they even still have a massive, room-size neuralyzer that requires the target to be placed inside and takes a minute to warm up when they can just use the pocket size version instantly?

They ruined a pretty clever bit by pulling out the mini version in the end. They should have just used J's modern neuralyzer if when they needed a portable one at the end. They could have had K marvel at the small size of it (like the way J marveled at the huge size of K's '69 portable phone in that one scene).