Okay, I didn't go to CHQ because Checky who is a 1500SP player of GuitarFreaks up there told me that everything is in poor condition currently. However, I did go to e-spot for about 6 hours or so, so I can let you know those conditions.
GFV7 ($1/4 songs, long ver. is 2 songs): No working effector knobs, doesn't matter. Sort with R-G-B-pick. Buttons have the springs taken out so they are really easy to push which is quite awesome, more arcades should do that. Volume is awesome. It's probably a better bet to play on the 2P side though because there's exposed wiring under the effector knob on the 1P side and if you accidentally hit it you could mess things up.
Drummania V7 ($1/4 songs, long ver. is 2 songs): Works great. Volume is good, pads are good (Checky claimed the red tom was acting up, but I didn't notice it).
Pop'n Music 15 ADVENTURE! ($1/4 songs): Buttons all work great. Machine volume is pretty decent, plus if you ask at the counter they could probably turn it up for you if you wanted.
Drummania V6 ($1/4 songs, long ver. is 1 song): Drum pads are alright. The pedal is hardly connected to the machine but it works fine. Volume is pretty decent.
GF V6: Didn't play this!
IIDX Distorted: Buttons were fine, the monitor lags a bit and the game stutters but overall it's okay. The turntables appear to be new and they work great.
IIDX DJ Troopers: Brilliant. Volume is great, there's a huge fan next to it, keys are great, turntable is fine, and the monitor is a lagless official Konami CRT. Great machine. I almost passed Scripted Connection A mix [a], but the arcade turntable spacing confused me.
Taiko no Tatsujin 12. Left side is "decent" according to TWF, right side is "fine".
Beatmania Complete Mix 2: Works fine, but it looks disgusting because the keys all have cigarette burns and whatnot on them. Monitor looks really crisp though!
Dodonpachi Daioujou: Works great. Sticks are nice and the buttons are fine too.
DDR Supernova 2: I didn't play this trip, but it's usually in pretty good condition. It's actually a Japanese upgraded Extreme, which is kind of interesting.
Also, there is a small Asian mall really near e-spot called Parker Place. Some good Chinese food there, and they happen to have a really tiny arcade called Game 828 which contains a few purikura booths, Battle Gear 4 Tuned (online connected), Maximum Tune 3DX+, and...GuitarFreaks and Drummania V7! Their machines are both set at $1 for 4 songs with long versions only counting as one stage. The volumes are great, and the Drummania works brilliantly but the pedal has the same issue as Acme's machine: when you let of it, it makes a big "CLUNK!" noise. Kind of distracting, but it's a neat place nonetheless.
GFDMV7 is pretty fun. The new V7 songs aren't necessarily that great (except for the new Thomas Howard Lichtenstein song and the Extra/Encore stages), but there's still a ton of great stuff from V6 and below.
Anyway, I went up with defiled and TWF and it was a great time! I'll post next time I'm going, as it would be cool to get a really big group get-together planned to remind ourselves of the old days when people actually played GFDM!