The Spit and the Dom are basically the same board from the nose down to the front fins.The paddle is pretty much the same where boards differ is in the turn radius with the Spit being closer due to the tail design and config.
Dom 6'6" : 45.2lts
Spit 6'4" : 41.5lts

That's where the difference resides and where the issues are coming from I believe.
Everybody's surf is different and what's good for someone could not be good for someone else. In my case I always try to stay close to the same volume range when changing boards.
Having the Dominator already I would have been looking maybe for the Hellfire. Still hybrid but very performant

I'd suggest going back to the 6'6". It probably doesn't matter a great deal if you get the Dom or the Spit, but in either case go the 6'6".

Another alternative could be to get a 6'5" Dom on CBD. That would be 42.5 litres as opposed to 40.6 for the 6'4" and 45.2 for the 6'6". That would normally cost a little more but maybe the surf shop you are ordering through will absorb that cost in view of your loyalty and not being happy on the smaller length.

Inciodentally, at 96kg I can see completely where you are coming from on the volume thing. I'm 90kg and surf the 6'4". To get the same feeling at 96kg I'd need to be on at least the 6'5" if not the 6'6".

The more I think about it I reckon the 6'5" CBD is probably the strongest option for you. That way you get the more turnability you were looking for, but brings you closer to the volume you are more comfortable on. You could even add a tad of width or thickness to the standard dims to the 6'5" to bring it closer to the volume on the 6'6".

PS If you weren't prepared to take the risk on a 6'5" CBD then I agree the 6'6" Spit would be the way to go.

Learn to paddle faster! Push the air out as you are paddling into the take off to get some more push. My guess is that you have been pampered with the extra volume of the 6'6" dropping nearly 10% is going to make a difference you you are going to have to work a bit harder. If it were just a case of lacking some paddle power to get in early I'd work on fitness but if you believe there are occasions where you've made the take off fine and find it just seems to run out of steam after a harder turn off the bottom then it probably is that it doesn't have enough volume for you. If any of the following sounds like you then go back to the 6'6" to avoid more misery.

I went from a Stretch 6'5" to a 6'1" and the difference in float was noticeable and I only ever got it to work on some waves. I went from sitting in the water around the lower ribs to the nipple line. Taking off was very balance sensitive, slightly off and a rail would catch or I'd just fall by overbalancing. It would go OK in clean waves, even small ones but they needed a bit of shape. On waves where I got off to a clean take off I'd push a bottom turn and find the board coming to a standstill and I'd be left standing in the pocket as the wave took off without me. Occasionally I'd get the right wave and make it down the line and complete manoeuvres without a problem which just made me think perhaps I just needed to work out my feet better on other waves. The sloppier the conditions the worse this board went too. The problem continually was speed, or a lack of it. It was reflected everywhere, in places where you want speed, like coming off the bottom, coming out of a cutback once speed was lost it was extremely hard to get it going again. The 6'5" never had those issues but I'd sold it and it felt a bit big (after I'd lost weight and fitness returned). After 6 months I gave up this thing just would not co-operate and I surfed the worst I've ever surfed. It was 6'1" x 2.625" x 19.25", I stepped back onto my After burner which was 6'6" x 2.375" x 19.25" and instantly surfed better. I found bigger fins helped a little to give it more drive but it was still nowhere near other boards I was riding - I gave up on quads for a while after that.

Then I bought a 6'4" x 19.75" x 2.5" bat tail (quite similar looking to the Stretch) and it went well, went great and got me frothing again. I bought the 6'0 dom after that and the froth continued and the FW addiction began!

Yeah I was going to suggest bigger or stiffer fins. Obviously won't help paddling. I tend to use positioning for an easy take off rather than volume.

Great response thanks heaps. Definitely pampered. Mrs had a laugh at that one!

LOL that's a luxury that the crowds do not afford here most of the time.

Ha prob why my wave count can be low sometimes!

Yeah, I was going to say, relevant, get those arms in shape or youll have that same problem on any board size downward.

Im about your weight and ride a 6 4 dom. Paddles well, I believe I could probably go to a 6 2. Stick with the 6 4 and your not going to regret it!!!

Really.... I was thinking of going a 6'5 el feugo but apparently they are an old model and the world has moved on a little....even so was still gonna get a demo and try it out.
What were you riding beforehand? What was your experience?

I'd second the option to play around with the fin setup. That should help you with the "missing sections" problem at least. I think paddling will come as you do it more.

the el fuego is a solid solid shape and it will be in our quiver forever. Don't think that the world has moved on...it certainly is a shape worth considering because it works so well..

regarding size, i think at your weight Breg, the 606 will suit you better and address the issues that you have mentioned!

Cheers and hope this helps!!