Here's (hopefully) an easy way to break it down:
As an example & using the two kites you mention; if you can imagine looking at both kites from the side, you would notice the Cat has a more 'open' canopy than the C4. Then, if you can imagine looking directly up from your 'pilot' position holding the bar, you would 'see' more of the Cat canopy vs the C4 if both kites were directly above or even downwind of you.
Why is this? These 3 strut so called 'open C' kites are (basically put) full C kites with the wing tips chopped back. So, if you have 10m of sail cloth and (let's say) 3m of those 10 is 'missing' from the chopped wing tips of the Cat, then it has to be in the 'open' area you look at as you look up. Make sense?
Therefore, you will understand why these open C kites (Cat, RPM, Park etc etc) are described as having easier accessible lift (boost) and an easier glide back down with not so much steering input required (read hang time..) It's a good, way to create reactivity to input and also power through the turns whilst still retaining easily accessible lift - all put together in a user friendly package.. Look at their history to date; they sell! Yes there are differences in aspect ratio & a full C will be jumped using different timing/speed of redirect etc. but I feel this is a good way to explain the essential differences.
Accelerate the same 'open' canopy (Cat in this example) through a loop and it will generate more lift (as opposed to a more closed canopy) therefore giving you the feeling of "punch" you describe in your question.
In the extreme, you may have heard, or read here that a flatter kite (Edge for example, using the Ozone company again) has and will scare most people sh1tless if it is allowed to develop power through a full powered loop.
Hope this
gives you a headache helps