Bi-wire cable or two complete sets of the same?

Question: Bi-wire cable or two complete sets of the same type of cable? Which is better? or is there a difference?
I have upgraded my system but have a set of MIT-MH-750-Shotgun speaker wires 8' long. Now that I have an amp with 8 hookups and speakers with the same, should I just buy another set of MIT-MH-750-Shotgun cables 8' long or buy a Bi-wire set and sell the ones I have?
Any thoughts or ideas?
I know we have some doubters here but I have added a second set of exact same wires 5 or 6 times. You know, used jumpers till I could afford the second run;-- BIG improvement each time. This was with different setups (speakers and wires) It improved things each time;so you know where I stand.
Hi John.

You're probably going to get quite a few differing opinions here but here's my experience; Bi-wire, where the "two" cables are in one sheath, is for the most part useless in terms of getting the benefits Bi-wiring can provide. I suspect that's a major reason why some enthusiasts argue against bi-wiring. When the conductors for the bottom section and the top section are that close together (one sheath), there's too much interaction for the benefits to be realized. Running to separate cables spaced apart eliminates at least most of the degrading interaction.

My suggestion is get another set of what you're already using. With a mono block amp for each speaker or with a stereo amp, that's going to get you the most sonic improvement.

You may be able to glean a little bit more info from THIS thread as well. .

Hope this helps.

I don't know about MIT, but Transparent does not recommend using two sets of networked cables for bi-wiring. The networks can interact, which would place the cables out of spec. I suspect your MIT cables would have the same reaction, but you should contact MIT to verify.
What you should do is talk to the people at MIT (if that is the cable you plan on sticking with) I heard they are starting to offer a trade in on older/used products, so you may be able to get some good value for the one you have now.