While I may not have the best cage in comparison to say Dizzy or Curbo, I do have LOADS of information concerning this matchup, so, here goes.
Seapeople is completely correct in this matchup from the looks of the write up. Now, basically, take the write up for Reptile and flip it. Sounds basic but here are my main points.
D1 is almost your best friend in this matchup. It pokes Reptile out of every attempt after a break in your pressure. For example...f3,3 into d1. If the Reptile player knows that the only option for pressure continuation after a f3,3 is to poke or crossup then you have them. Of course, d3 is the better option, however, in the corner after a blocked f3,3,b3 your best option to continue pressure is the d1. At any point on the screen, d1 will poke Reptile out of elbow dash, EX elbow dash and slide. I am personally not 100% about the EX slide and quite frankly, if the Reptile player chooses this method to escape pressure, chalk it up as a win for Cage for 2 reasons: waste of meter, and from what I can tell, cage can randomly (if not 100% of the time) poke Reptile out of the EX slide with d1. I was lucky enough to get matches in with Showtime at MLG Raleigh and the d1 was amazing. Not saying he is the best Reptile on the planet or that my Cage is by any means, however, we can all admit that he is among the best to play the game. What I find "abusable" against a player of this caliber, I find viable in the matchup.
DO NOT STAND BLOCK. A good Cage will blow up a Reptile (or any character) that just loves to stand block. Be my guest and eat 1's and 2's the entire match. That opens up a ridiculous array of pressure options for the Cage player. 1 2 d3 and the 1,3 string followed by EX forceball or d3 and d1 mixups. Add that to the f3 pressure in which Reptile has a very hard time getting out of and you are headed for even more trouble. Trust me from the Cage perspective I personally hate crouch blocking opponents. Tougher to continue pressure against and less "free" meter in the long run.
Cage will rarely if ever attempt the EX forceball for obvious reasons.
1.) The first forceball will whiff a standing Reptile, therefore, no reason to attempt it.
2.) The only way to connect with the forceball frame trap is 1,3~EX FB or f2~EX FB...gotta be standing for those to connect.
3.) Most Cage players would prefer to use that meter for breaker. Since you don't need it for frametraps, play an overaggressive style with the d1 pokes and you minimize risk while holding breakers for the majority of the match. Just don't get carried away...f3,3,b3 into d1 every time is not practical. I'm simply saying you can abuse it.
In the corner:
Cage corner pressure against Reptile is a little different than most. Reptile players LOVE to use the EX elbow dash to escape the corner for obvious reasons. Since Cage is able to poke Reptile out of the EX elbow dash easily (especially in the corner) Reptile is forced to make a quick decision. As a Cage player I love to abuse f3,3,b3 into d1 in the corner simply to bait an EX dash for meter drain or to bait a jump. D1 pokes out the elbow dash and I can continue pressure, however, it can still be read and jumped over granting Reptile some pressure of his own. This is the basic ground floor of the metagame in the corner between these two characters. After that break in pressure the Reptile can choose to low block anticipating the d1 to block it and pressure or jump to attempt to blow it up. A jump of course gets blown up by the b3 or standing 1 into a nutpunch reset so as a Cage player I'm wanting them to jump when I expect it, AA, and reset the pressure. Of course my goal as Cage is to pressure so well that I never use the b3 ender, and mindlessly knee them in the corner and face palm them in the chest for all of eternity but that's not going to happen 99% of the time. Just some food for thought with that d1.
As for midscreen, Cage treats it like any other matchup minus the use of forceball frametraps. Use of 2 and f3 pressure mixups and if the Reptile wants to stand, 1s, 1,3 and f2 forceball pressure are my options and poking often is my friend. I also find 2,1 mixups to be extremely helpful. Reptile has an easier time getting out of those so ending the string in the launcher and 2,1 into d3 is as free as it could possibly get if you know what you are doing.
Seapeople has previously spoken on the EX dash pressure. Cage can d1 in the middle of it and even b3 if he's good enough but overabuse of that isn't recommended from my perspective.
In my overall opinion (and as previously stated) it is a match that revolves heavily on meter and the ability of the Reptile player to keep Cage out or at maximum d4 distance. That d1 is a monster for Reptile to handle, he can't keep out Cage forever, and he can't poke out of shit. From my personal experience and matchup knowledge, 6-4 Cage.