I only played D1-D3 (was too laggy to play on), and here's what I have to say about the Ultimate FSC.

-I'll start by saying that no one is really going to play this on the live game. It will be way too expensive to run with way too little reward. The crowns/heat acquired did not seem much different from regular FSC, and the sheer amount of CE required to make up for mistakes will be ridiculous.

-The Slag Guards need to be changed a bit. They have an extremely high amount of health (even in a solo run), don't spend much time facing backwards (after their stab animation), and give absolutely no reward. I couldn't believe it after I had killed the first one. The toughest enemy in the area gives absolutely no reward. Give them drops and lengthen their immobile time and it might be playable.

-The first room of D3 (D26 in the live server) reminds me of the arcade games of old. It was designed to make you spend your quarters. You are stuck with a ring of spikes and a center totem. I had no trouble up to this point. If I was playing latency-free (I was experiencing a ton of lag), I could've solo'd up to this point without a death. Even with lag it wasn't that difficult. This room, however, is ridiculous. Without a Nitronome you are doomed from the start of the second wave, thanks to it being triggered BEFORE the first wave ends, along with a Slag Guard in cramped quarters. I think the totem needs to go here.

-Aside from these complaints, I enjoyed it. If a few things go unchanged I definitely won't be playing this live, though. Why run this when you can get the same thing from normal FSC?