Originally Posted by Kodiak
I guess the only way to really know is bite the bullet and try something v4 but I find it difficult to pay more $$$ when I already really love what I have.

Given the emotions you've described, I say keep the M60Ti and get yourself at least one sealed sub. There is no point in waiting for a sub because you will always need at least one.

House of the Rising Sone
Out in the mid or far field
Dedicated mid-woofers are over-rated