They're comparable to the Canon L equivalents (well, the 35mm outperforms the 35mm L wide open and the others are not far behind) and, in my experience, they outperform the Cooke S4s and Zeiss Superspeeds as well in terms of sharpness and micro contrast wide open. Granted the mechanics and "look" are worse, but just because you CAN spend more money doesn't mean you need to, especially when the rest of a decent package (tripod, camera support, matte box, filters) can add up so fast. I know a lot of Scarlet users are using these lenses, and that's the same price range (though I'd much prefer the 1DC!).
That said, if money is no issue, the Canon cinema primes seem like the best things going; the selection is just very limited and the prices are high.
First off, the CP.2 Super speeds aren't even available until October 14th, so how you're qualified to say the Samyangs outperform them is beyond me. Maybe you're talking about the older Super Speeds, but that would be just as ridiculous. And are you seriously trying to say that the Samyang outperforms (as in are better than) $20,000+ Cooke Primes? Are you out of your mind or just joking?
I mean don't get me wrong, they're great for the money and if you're on a budget, but you're giving them way, way, way, way too much credit. Yes, the Samyang 35 is comparable to the 35L in terms of performance, but that's the exception, the rest of the Samyangs have gotten pretty mediocre reviews. So let's say he does get the Samyang 35, what about every other focal length?
How you can slam Cooke's and Zeiss CP.2's yet be cool with the Canon's are beyond me, since the Canon Cine's aren't even available, how do you have any idea how they perform?
And OP was clearly interested in the Canon Cine's and the CP.2's, I suggested the Duclos modded ZF.2's which are reasonably priced cinema lenses. But if a guy says he wants a Lamborghini and you think it's too much, try talking him down to a Corvette or something first, not a Geo Metro.
What are you talking about? Super speeds are all time classics. I am referring to the Mark IIIs. They're super35 only, of course. They are a bit older (1980s and 1970s) but still command $35,000 used for a a good set. Divisive lenses due to bokeh, harshness, coma wide open, and poor close focus but they are my favorite cinema lenses in some respects...so small and fast. But not as sharp as the Samyang 35mm! I am also dead serious that this lens is as sharp if not sharper than the Cooke S4 primes, but the Cookes have a beautiful dreamy effect (that actually reduces resolution) and gorgeous bokeh and no breathing--all I'm saying is, resolution isn't everything!
Fwiw, I have the 85mm Samyang and it's pretty close to the best of the best fast 85mms. There's a bit less resolution, but micro-contrast is still excellent and bokeh is fine. Build quality is just okay, but your comparison is ridiculous. Maybe MPs to kit lenses is Lambo to Metro, but MPs don't even cover APS-H reliably (though they are probably fine from 14mm+)....this is more like Benz to Bentley...you pay for fit and finish, performance is better but with diminishing returns.... Worth it to some, of course, but diminishing returns is key and performance and utility wise they are in the same category as the CPs. Not MPs or Cookes, of course, though performance is surprisingly close in terms of sharpness alone. If you put a high end cinema lens on a still camera and shot it against still glass I think you would be surprised--performance is not that much better. The reduction in breathing is something, but the CPs breathe a bit and aren't even true cinema lenses. (Which aren't really options for the 1DC, anyway, because of its oversized sensor.)
Canon cinema lenses haven roughly the same designs as their L lenses except better coatings and different aperture blades and build quality is better...so speculating on their quality is easy and they will trump the CPs for the price. 24mm f1.4 II is a great lens and I can't imagine the Zeiss lenses are worth it by comparison when price is taken into account. They are pretty sharp but slow for the money and the super speed CPs should be expensive for a $10,000 kit. Modified ZE lenses seem like a better idea, but again performance won't beat Samyang or Canon to a field significant extent. (Canon L is a bad choice, though, only since there are no hard focus stops!). Zeiss lenses do have nice coatings and good micro-contrast and flare control, so that is worth something. Whatever you can afford is best, though--having the right focal lengths, filters, and useable mechanics is 1000X more important than a little resolution at stops you will almost never use--who shoots wide open (except David Fincher) and gets away with it? t2.8-t5.6 are the stops that count--all these lenses will be great at those stops.
The 11-16mm will be fine if you don't mind soft corners with a little CA and zooming in to 14mm or so before using it. It works great on the Epic, usable with major vignetting even at 11mm, and kind of works at 16mm on full frame. I wouldn't recommend it if you can afford better, but I wouldn't recommend the 17-40mm f4 L, either, which is optically poor. These are extreme UWA focal lengths of course, cool for music videos and cramped locations but not classically useful.
Btw, a normal cinema kit needs to cover the 18-85mm on super35 (approx 24-110mm on APS-H) range and then wider or tighter or zooms as needed for the specific project...no one wants one or two good lenses if they don't have the proper focal lengths and in terms of IQ you will not be able to detect a difference between any of these lenses at normal stops. You are paying for build quality; yes it is worth it but not to the exclusion of having the right focal lengths. It is worth it if you plan to rent, though. A Zeiss CP kit with appropriate focal lengths will rent over the alternatives, I would wager, because of the name recognition, important to less experienced shooters who don't realize they're just expensive Cosinas, not that there is anything wrong with that.
Also get a full complement of NDs: .3 .6 .9 1.2 1.5, a polarizer, a set of diffusion filters if you can afford it, a .6ND hard, soft, and attenuator, a follow focus (not cheap) with whip, and tripod of course...