Have not ridden them, but since it's been all quiet in the response department, I'll offer my two cents:

1. Both are great race bikes. Duh, I guess.

2. If you like to control your suspension firmness yourself, go Scott with the Twinlock.

3. If you don't want to be bothered with that, go Epic, and let the brains do the thinking, while you concentrate on pedaling.

 

I love my 2018 Spark RC WC. From all I’ve seen and read you either love or hate the brain and there is no inbetween. So regarding that I’d say definitely give the Epic a try on the trail before you buy. I was at the same crossroads a year ago and based on all my research went with the Spark. Personally I like having the control (TwinLock).

I will say the lower BB of the Spark did take some getting used to and I had plenty of pedal strikes for a month or two. However the handling and downhill confidence of the “in the bike” feel has been great. For reference I’m 6’1” on a Large frame.

 

Came from an Epic. And as stated above you will either love the brain or hate it. For me i could just never get the ride i desired. Stiff and soft if that makes since. Epic i always felt like i was pogo'ing off the big stuff. With that said mine was a 15 model year. Supposedly the new Epics are plusher compared to what they used to be. I dont know haven't ridden them. My 2019 RC WC is the bike i always i wanted. It is stiff while riding but soft when i am hitting stuff. It is very efficient. I love the twinlock, it gives you the option to do what you need. I use full open or traction(middle) mode. Never have locked it out. I have some fire road climbs where i lived and the bike is so efficient i have never had to go in full lockout. My .02