Anyone ever tried 2x100Watt Bi-Amp Vs 200 Watt

Wow. Lots of opinions. IMHO, a good 200w is superior in terms of power availability. The reason is that most of the power is utilized in the bass and with 2x100, the woofer/LF will still see only 100w. One can argue that bass stress will not affect the HF with 2x100 but by doubling the power to the LF, such stress is minimized.

Also, bridging is different from 2x100 and requires a phase inversion device. The result is usually more than 200w but places limitations on the impedance sensitivity.

Speaker impedance neither drops nor rises with biamping as a rule. There are few exceptions. If Ngjockey is referring to the input impedance seen by the preamp, that does drop but most amps have such a high input impedance that even halving it still presents a reasonable load for a decent preamp.

Kal