Grace Design m108 vs RME Fireface UFXII vs Grace Design m801mk2

[EmilieM]

Hi everyone,

does anyone have experience with the Grace design m108 and the RME Fireface? How do they compare sound wise?
I am looking into getting one of the two, to get a very clear and authentic sound for voice, with four mic inputs.
Are the preamps of the Grace better than those of the RME?

Also, what about the Grace Design m801mk2? No audio interface in there, so how does it compare to the m108 and why is it so much more expensive?
Does an external mic pre like this one make a massive difference sound wise, compared to the sound of the RME interface for example?