>>bridged amps were a concept for more power,
Bridged is not the same as balanced.
Yes, bridged/balanced does allow you to reach higher power. In the simplest terms, it lets you swing at most for double voltage (which technically would let you hit 4x power... but most amps will hit a current limit well before that).
A bridged amp is literally two separate amp channels where the second is running an inverted signal. Both channels reference to ground and would play normally if you connected a speaker at one end and grounded it at the other. But in a bridged config we smoosh the two positive outputs together across the speaker to generate your double voltage swing.
A balanced amp definition can get fuzzy; I'm gonna gloss over the whole impedance thing and give this slightly different take on it: it is not two separate amp channels. Yes there is a positive and negative leg that are inverted phase from one another, but there is no ground reference. The "channels" reference across to each other in the circuit, not to ground. Do NOT connect anything to ground.
You can also parallel an amp output. I'll let someone else take that one.
>>similar in concept to balanced ic's,
No. Balanced interconnects have nothing to do with power transfer and have all to do with noise rejection and removing ground from the equation which is often a source of noise itself.
Ground loops are a known thing and frustratingly difficult to track down. Dirty grounds are a known and measurable issue. Sometimes you're lucky and your ground is fine. Mine is so bad that my multimeter can't even measure the bloody thing because it jumps so bad. If I have the option, I use balanced IC's all the way and my noise issues almost completely disappear.
Here's a fun thing: balanced does not mean the negative is necessarily inverted from the positive. They merely have to have equal impedance from the ground to ensure high common mode rejection at the receiving end. Heck, the negative leg could really just be driven at 0V, which is not the same as making it ground. Oopsie I used the ugly impedance word. Technically on a balanced amp the negative side could be 0V as well.
>>they had tones of distortion,
Nope. A well implemented balanced (even bridged) amp will exhibit lower distortion. Mostly even order is reduced (I might be mistaken on that). The caveat here is that balanced/bridged configs are more complex, so improperly implemented will indeed product more distortion. By that token though, improperly implemented anything will result in distortion.
>>last time i checked they were confined to car amps,imho say no no to balanced ic's
If your sole reference point for balanced/bridged anything is car audio... well ok I can see where your bias comes from. That is an industry that values pure volume over fidelity, and has extreme cabinet volume constraints as well as harsh operating conditions and incredibly pi$$ poor power tapping off the alternator/battery.
Ugh past 1am, time for bed.
