Anyone tried using the flat SE exhaust gaskets vs the old style beveled and what we’re your thoughts. Good, bad etc?

I used them when I fitted the two into one on my bike.  First time I have replaced them so cant speak for the older style, but the flat SE ones were easy to fit and have been on for about four years.  No issues at all. 

I also went to the flat ones when changing exhaust. Seem to work ok, although I have read on US forums some people put two in each exhaust port. Have no idea what exhaust they are running.

My take, if you are confident your headers are near a spot on perfect fit and you can snug them into the centre then the flat ones have the advantage of not squeezing out into the port thereby restricting flow and costing you power, if you are a bit off they don't seal well, I've used them a few times but I like the ease of the tapered ones, more forgiving, just don't overtighten them or they will do what the flat ones don't.

Likely makes fuck all difference, Id just be matchin em to the header style.

Thanks lads. 

They were V&H two into one that I fitted to mine.  07 fatty.

Looking good. After trying to tame my VH BR 2-2 on my 110 Dyna, I chose the same system you’re running. Should be quieter as it has a proper muffler.

Runs really well.  Had long shots on it before that and was way too loud.  These pipes sound awesome as well.  Deep tone. 

Old Style flat ones...LOL... We call them Evo Exhaust gaskets and have been around for 30+ years.  very good and while they suggest single use they can be reused a couple of times.