Clubstep: harder ships, but simple memorization parts.
ToE2: Slightly easier segments IMO, but more memorization, also it's more fast-paced.

Also, by the 78-80% ship, you mean that slow ship before the last UFO? It's fairly easy, you just need to tap for long enough. If you're good at normal ship, it shouldn't be a big problem.

Honestly it's hard to tell which is harder, even if I beat both to compare them. Clubstep is fairly easy till about 70%, where the ships get tougher (and I'm bad at mini ship, so I struggled with it a bit), but ToE2 has harder coins and more memorization, but it was VERY easy for me when I practiced on a copyable, I just had problems with the first ship and second UFO which didn't jump like I wanted.

I'd say ToE2 is slightly harder, even if I've had 1,4k attempts compared to 2,2k in Clubstep. I could go fairly well until about 80% in Clubstep for a long time, but in ToE2 I struggled even on the first ship until I got a good moment when I felt well and determined enough to learn the whole level.

EDIT: Also I think I'd have less attempts in both level if I wasn't so desperated to play as a more noobish player. Not to say that after a long pause, I beat Clubstep in like 100 attempts and ToE2 in almost 300... but well, maybe I just remembered the levels more when playing as a newb? Who knows.

Clubstep: 900 attempts
ToE2: 2,000 attempts

Clubstep is extremely easy with really no parts that were hard for me. I didn't even rage on it.
ToE2 has some parts that slowed me down a lot, such as the part at 80%, and the UFO at the end (which wouldn't usually be hard, but you know, nerves). I raged like crazy on it.

In my opinion, Clubstep is easier than Electrodynamix. I can 1 attempt Clubstep (just ask my friend).
It takes me a few attempts to complete ToE2 before fully completing it. There are a lot of stupid placed to die, so that's one of my other struggles with this level.

The ship parts in Clubstep are very open, so there aren't many ways to fail. Super easy.
The ship parts in ToE2 are a lot more compact and cramped with invisible blocks everywhere, so it's hard to see what you could die on.

Clubstep is a very easy demon in my opinion. There are not many demons I can one attempts.
ToE2 is just easy. There are some easy parts, but there's always that one trick that can ruin your run.

tl;dr Theory of Everything 2 is harder.

Theory of Everything 2.

Why did I choose Theory of Everything 2? Because just like other people said in this thread, some parts are easier than Clubstep and some other parts are harder than Clubstep. I will mention the easy parts first: The wave (at the drop) looks easy and it's actually easier than Deadlocked. So the first wave parts should not be a problem (except for the 2nd coin, which can be problematic to some players who can't do the wave accurately.) Don't forget the last wave is actually easy as well too. And the beginning (obviously), there are obvious traps like crossed orbs that you shouldn't tap in or you'll go in the wrong way and crash. You already know where to go in that part. And the slow cube part at around 70-77%. It just looks easy and you should not have too many problems there.

Now the hard parts, you know the ball part with a bunch of fake blocks right? Yeah, that requires memorization. Or if your eyes are good enough, you can see that some blocks have different colors than the usual fake blocks and that different colored block is the real one. Now the first and the second ship part, it looks ridiculous at first. But if you pay attention to the invisible blocks, you may have no problems in there. Ball part after the first ship part also looks ridiculous at first. But when you practice it, you'll get used to it. Also the 78-81% part, which is the last ship part. When you tried it the first time with a decent ship skills, you might have a problem there. And it's probably the hardest skill required part in ToE 2.

That's what I thought about Theory of Everything 2. I've spent 2900 attempts to beat ToE 2. That was back in early 2015.

For Clubstep, it might seem to be easy because of not too hard memorization and ship skills. And the most parts are easier if you know where the fakes are. If you don't, then you have to practice it. I spent like 2700 attempts to beat Clubstep (back in early 2015).

In conclusion, ToE 2 is harder than Clubstep.

Both were ~4300 attempts for me (I beat Clubstep first, and those two were my first demons), and thus are pretty much equal, so I voted Clubstep to even the odds.

ToE 2 would have been harder if you asked this question early 1.9, when wave was ridiculously hard, now, after weve gotten used to wave and its just like every other gamemode, clubstep would be harder. I wont take attempts into account (even tho i have more on clubstep), because you need more coins to unlock ToE2, but after i completed them, I tried 3 coins on both. i know some coin routes may be easier than the proper way, but in general, clubstep has more hard parts (first mini ufo, upside down mini ship near the end, etc.) and more balanced out in terms of difficulty, but ToE2 is easier but has a few difficulty spikes (~80% ship).

this is why i think clubstep is harder than ToE2, theyre both really easy now, but for people who are just starting to beat demons, go with ToE2 first.

Clubstep is harder than ToE II imo.

Since clubstep is quite easy the first 60% of the level, but the rest is hard, espeacilly the ship parts.
ToE II has some hard parts, but some extremely easy parts as well, making ToE II really easy.

I've actually beaten ToE II five times, cuz i was bored, while I've only beaten Clubstep Twice (and Deadlocked once)