I'm not sure if Orca and Protek are the same as stated above, but if so, it's really surprising because Protek batteries suck. I had 2 100c packs and they swelled up after 1 and 2 uses respectively. IR was not bad but not as good as Orion pack and EAM pack. Orion is way more expensive than Team EA pack but IR is lower.
I want to try Team Scream's batteries too. They are cheap and they say IR is super low. Anybody has any experience?
And side note: 5000mAh is good enough for up to 7minutes's stock racing. For mod, I would get at least 6000mAh. As mentioned above, once the battery's over 6A, it gets quite heavy. No reason to add weight when you only run stock racing under 7 minutes. My local track runs 10 minutes main for some weird reason so it's sort of harsh on my batteries. But so far even 5A EA battery for 17.5T has been holding up well.