Practically speaking, is there room inside the pedal train cases for extra stuff? I'm considering downsizing a bit and moving to a pedal train metro 24. It would hold two Eventide H9s, Xotic BB Bass Pre and a looper of some kind (maybe Pigtronix). I would need space in the case for a volume pedal and a power strip with a long cable to get to the wall. Thanks.
It depends on how much bulk would bother you. If you're talking about a Mooer or other mini volume pedal, sure, no problem. A Tapestry Audio placed sideways between the rails or an Ernie Ball Jr. placed flat will create maybe an inch of bulk. However, there is space for the cables under the board without creating extra bulk. I wish it had a front pocket like the PT mini case.
Just remember with the metro series that there is not room beneath the board to mount a normal power supply (voodoo Labs, t-rex, etc) due to the thickness of the power supply. (unless you are happy to add larger rubber feet under it like i did) Re the soft case. When I had my pedaltrain classic jr I could put a additional items like a tablet holder, guitar leads, etc in the case without much difficulty. A volume pedal might be pushing it though (as especially since the metro is a lot narrower than the classic jr.)