I own a Summit Cobra, and API Bowhunters Grand Slam, so I' m not " taking pride" in a product that I bought publically and hate to say I spent money on a worthless product! I' m a bow only hunter and take my stuff seriously. Here is my review for what it' s worth between the two:

API vs Summit (models I own)
chain vs cable: no difference, both are very stable and lock on solid

pins vs latch: I hate aligning holes for pins and you have to tie pins to stand to not drop. Summit: hands down in this category for setup/tear down during darkness. Latches are so easy.

Backpacking straps, foot straps, and upper stabilzer strap:
API has (on my last years version) the d-ring push-strap- loosen strap type of straps to tighten (except the stabilizer). The stabilizer strap has a heavy buckle assy that seem to always hit something metallic and make a " clang" .
Summits have the easy pull to tighten strap' s that lock with spring loaded buckles. Basically, pull once and forget. Very easy.

Packing:
API has a somewhat different method of turning the seat portion 90 degress and placing into the bottom half. Ingenuity with stabilizer strap will allow cinching of both halves together to prevent clang while walking to/from stand. And will prevent using the 3 straps included with the awful push/pull buckles.
Summit is one-way only I believe and is fitted for each other. Wrap the stab strap around both halves, cinch, and done. (I can' t speak for the new folding models)

API has better padded arm rest' s with the velcro camo covers.
Summit uses zipties that you need to make sure they are positioned correctly or they can " scratch" when standing at the moment of truth. They need to be trimmed well.

API' s upper-half arm rest' s are a little longer which makes a good thing to hang your bow from. I apply felt type padding on the lower half to protect the bow string from rubbing the metal portion. And they provide a nifty ditty bag that is handy.

Seats:
I find both brands are comfortable. Between the old inflatable and new foam seats in the Summits, I prefer the inflatable because they move out the way better when standing.

Price is near the same.

I did have a Summit Viper that the weld looked like it was coming apart. I called Summit and with no questions asked, they sent me a new stand and provided a pre-paid shipping ticket to send the old back. No questions asked. I asked them to send me a Cobra instead and they did. I didn' t like the front bar anyway!

That is all!