Yeah, the Brown Dog has been my favorite synthy and/or funky fuzz for years and years now. It has a very nasally quality that doesn't always sound great soloed but cuts through really well in a mix. The JohnK version is ideal for a tiny board and sounds the same so I'm happy.
And yeah, the Volto and the (now discontinued) Sanyo are obviously not isolated supplies so there can be some issues. Everything in life is a compromise of one sort or another.
I bought the Volto initially to make an at home practice board. Turbo Tuner, Overdrive (Darkglass VMT I believe), Ditto and Enabler. It meant a super portable setup that I could use with headphones and my phone or iPad to learn songs. I still had my big board which was a PT-2 (with the flight case) and 10 or 11 pedals. But I got tired of lugging that thing around and tried to see if I could shrink down to just the Mini with the Volto.
I do get nervous about relying on a rechargeable battery but with the added power pack and the ability to plug the Volto in at gigs (I always bring the AC adapter and cable) I have had zero issues so far. If it fails it will be because the Volto itself craps out. Fingers crossed but the early returns are really good.
I miss having things like phasers, delay, my IE Subterranea and Polytope for (massive synth sounds) but I'm loving the portability.
It's this one.
Amazon.com: Poweradd Pilot 2GS 10,000mAh Portable Phone Charger External Battery Pack with Fast Charging for iPhone, iPod Touch, Samsung Galaxy, LG, HTC and more - Silver: Cell Phones & Accessories
There's actually a version (for the same price) that has a 12,000 mAh rating and a display of the power remaining. But I like the form factor (for velcroing) of the 10,000 mAh version better.
Amazon.com: Poweradd Pilot S 12000mAh Portable Charger Dual USB External Battery Power Pack Smart LCD Display for iPhone 6 Plus 5s 5c 5, iPad Air 2 Mini 3, Galaxy S6 S5 S4 Note 4 3 2, Nexus, Motorola, Blackberry, HTC One M9, LG G3, other Phones and Tablets - White: Cell Phones & Accessories