Back when I bought my A3, I got it without even listening to it, just plain reading and research. and it came to me as one of the best decision I've made. Coming close are the Fidue A83 are Jvc fx-1100.
As for big sound, I can say that the Xba-A3 is one of the IEM I've heard that sounded like full cans.
Bass is prominent, the strongs are the clarity and soundstage, coupled with the bass brings a full-bodied sound. I'd recommend the Upgrade cable if you like dark and warm sound signature.
The A3's doesn't require as much power, so your LG would do the job. If you're into more bass and power, the headstage arrow amp is one of the great choices. The C5 is decent too, but portability wise and sound difference after pairing, I wouldn't quite recommend them.
The average isolation means that you'll probably hear outside noise while listening to music. In my experience, regular music at normal volume blocks out all sound, unless I'm playing like classical or soft music, that's when I can hear some outside noise. I wouldn't call it a con tho it doesn't affect the expeience with A3, and it allows awareness of your surrounding. Secondly, people will also hear your music because the A3 is sort of a 1/4 open earphone. There's a tiny hole at the side of the driver that allows air to travel in/out. Unlike other semi in-ear like the Dunu Titan 1 that is "really" open, where people can hear your music loud and clear, the A3 does great in keeping noise level as low as "closed-earphones", so unless you're listening at volume that kills your ears, people around you probably won't hear much of your music, perhaps only some tiny audio noise from a distance.
Well, as for frankenstein, i can't argue much. Butt..It sounded too good for me to even care about how it looks(I believe we all do). I'd say Frankenstein is liveable.
An early welcome to the franken community.