It seems to me the magni is more audiophile grade with coloration of the sound. People mention smooth treble among other things.
I'm going to be producing music mostly so I wish to avoid hifi type style amps if possible. Also its over my budget.
But I suppose some slight coloration might be OK and it will probably last me a long time and it looks great. So definitely an option. Now if they only were sold in Sweden :/
Ummm....HiFi means "high fidelity." That basically means "true(r) to the sound," ie the original signal.
That's not absolute so when you crank up these amps you'll still end up less true to the signal since they'll start distorting, where you'll have some amps getting sharper treble while others get smoother treble; few among the powerful hi-fi amps get appreciable distortion at the low end since there power quantity and not clipping tends to be something more important than absolutely low THD at those frequencies. Some amps can pile on audible noise which can obscure the low bass, even offsetting the gains in cranking them up, unlike for example the O2, Meiers, and Violectrics that across the board stay totally quiet unless there's noise from the source. If you have a high output HiFi amp, as long as distortion and noise are well managed relative to output, you're highly unlikely to start hearing a lot of obvious distortion or even coloration at safe volume levels on anything but the lowest efficiency headphones (or speakers, whichever the case may be). If it runs pure Class A you won't get any crossover distortion, while some Class A/B amps have high output and may have high Class A bias, so at safe volume levels even on dynamic peaks you're essentially running in Class A.
A low power, high output impedance pro amp is going to give you a lot more audible coloration with their very low damping factor that gets you more driver distortion, plus amp noise and distortion, if not outright clipping the signal running out of power. In short, being labeled a pro product does not automatically mean that is the standard for transparent sound when you have all these problems.
"But then why do pros use them?" Well, they don't use them for mixing and mastering, just monitoring while recording (or broadcasting), then they check their mix on them later (which needs to be done on different systems anyway, like how Abbey Road has B&W 800 series speakers). They're also in a recording studio with acoustic treatment and no family members watching TV or talking, so a 300ohm headphone can get to a usable enough volume and also with impedance like that doesn't have any real problems with the damping factor.
Here's something similar and related to "pro" perceptions. People will claim HD650 is "audiophile warm" while the K701 is "transparent and detailed, like what pros like." Reality: K701 rolls off the bass early, which means the pros are hearing a narrower range when they use this. If the bass ends up bloated on a mix checked on the K701, maybe it's because the engineer overcompensated for the bass he can't hear. The HD650 has a smoother graph, which doesn't mean "smooth treble" is automatically bed when you compare it to the treble peaks on the K701. if anything some audiophiles would like the K701 for another reason: the wider and deeper imaging.