Groove Radar is all right right but Max1 version is the best.
Anyways enough of that.
Upgrade Kits: Make sure this works on all machines, not just Supernovas, also make sure you shipped the kits with the new pad panels and seasors.
Cab and Pads: I heard that Konami may not keep the cab design from the location test. If this is the case, with your new choice of Cab Design, please keep your new pad design (or inprove it even more) alot of people mention the new pads rock. Also the 18,000 price tag is just nuts, you really need to lower it, even 12,000 or less is waaaay better.
Shock Arrows: Don't always use Shock Arrows on all four arrows.
Ultramix/Universe/Hottest Party Songs on AC: Don't know if this is too late for X but this is can be still used for future arcades but please add songs from these games, there is a few good songs and charts in these games.
Link Mode: I realise that DDR X CS US does not have a Link Mode for the arcade, so I am guessing the other versions (Europe and Japan) will be seeing this after the game comes out. Please find a way for US Players to take part of this feature as well.
Challenge on older Songs: Bring some life back to some of the older stuff, just don't turn them into Expert Charts with Shock Arrows, if you want a idea on what to do, make these charts range from 14 to 16 or something like that. I realise that alot of 14 to 16s are older stuff so this would be a good idea.
That's about it for now.