Bullets vs. spades and/or wire gauge?

When I started doing pro sound way back in the day, I made all of my speaker connections with industrial grade bullet connectors soldered to 12 gauge PVC jacketed wire.  They were durable, reliable and made for very fast set-up and knock-down.  The 12 gauge was fine for the 25 to 35 foot distances needed to the stage monitors and main stacks.  I never saw a reason to question this formula until fairly recently.

My rig has fairly short distances between the amp and speakers. Solely because of how my built-in audio cabinetry is made, I used 17 feet of 12 gauge on either side with compression-fit gold bullets. The length gave me enough slack to snake everything through the conduits, easily make connections and the 12 gauge was sufficiently low in resistance for the distance involved.

I had browsed past a thread here some months ago where someone commented that spade connectors offered a better sounding connection.  No engineering justification was discussed, but it did get me thinking.  The surface area of a traditional (leaf-spring style) bullet in contact with the inside tube wall of the terminal is pretty small, while that of a spade is visibly larger.  Moreover, there are 3 contact points:  The fixed male end of the terminal, the moving female terminal cap and the threaded terminal shaft itself.  At the time, I concluded it was a super-simple and inexpensive experiment worth trying when I had a free moment.

So, fast forward to the present.  I'd had some nicely plated spades sitting around for a few years and just last week stumbled across a very good deal on some 10 gauge silicone jacketed pure OFC stranded wire with 462 strands per conductor.  Finally put everything together on Saturday and immediately discovered that silicone jacketing is far easier to snake through conduit.  A pleasant surprise.  Then I fired my rig up and did some listening.  I immediately noticed that the resolution was better, and the bass in particular exhibited improved frequency response.  Going right down to the bottom of what my speakers can produce and enough so that I now have to rebalance my subwoofer on the HT capacity of my system.  A very pleasant surprise.

Not having the electrical engineering background necessary to substantiate the physics behind my observations, I'm hoping that folks can give me an idea about how much of what I'm hearing may be due to the improved contact area of the spades and how much is due to the slightly lower resistance of the heavier gauge wire.  I look forward to your input.