Hegel is a brand that is not that well known in the UK and dealers are few and far between. I'd hazard a guess and say not many on this forum have heard the H80 let alone compared it with the Nait 5i and the chances that they have partnered it with CM1's is very slim indeed.
If you have the opportunity then go audition for yourself. The Naim has a distinct sound that is not for everyone and the Hegel has an inbuilt DAC. Do you need this facility? If not then money is better spent where the costs are concentrating on the amp components solely.
Very much 'try it and see' as they are very different amps. However if it were my money it would be on the Hegel if only for it's added flexibility.
Oh and I think it looks nicer 🙂