A few things make me hesitant.
First, I have no experience with RSA's portable amps. The fullsized RSA amps I've tried I haven't cared for personally; at least, not enough to buy them over other competitors' amps (though his casework is very attractive looking). His portables seem quite popular however.
The other issue is that I'll be getting the JH-3A + JH16Pro. It wont be my only CIEM, but it's certainly going to be a main player. There's an adapter to let you use the proprietary cable with other devices, but I'm wondering if it would be possible to get a balanced cable built for the JH-3A version of the JH16Pro (since it uses two sockets on each earpiece instead of one?). Like, can you use a standard (one socket) JH16Pro cable on it when using another amp? Seems a little silly to invest so much money in a cable that can be used by one custom, a custom that already has its own proprietary amp that I'd be ignoring in favor of the Intruder.