Hello!
Yes, the 32 Ohm DT770’s would work for mixing on a laptop…though I’d recommend getting comfortable with their specific signature for a while first. Their slightly elevated bass and speedy treble mean that, when making a final mix, you might accidentally lower the bass and treble values in your music too much.
That’ll make your tracks sound more neutral on your 770's…but will make them sound more mid-forward on other people’s neutral headphones or speaker systems during playback.
In other words, without some care, it’d be easy to craft a mix that sounds great on 770’s and a little weird on everything else.
The studio tasks that the 770’s are best suited to are monitoring applications, where you’re trying to pick out flaws while field recording, or isolate yourself in a studio while recording a track in a recording booth.
However, I don’t think this is all as much of an issue as some folks do, and I think as long as you give yourself a couple of weeks to learn the sound of these headphones on them you’ll be mixing just fine. I’m not pretentious enough to tell people what they should be mixing on, and I still personally find the 770’s response accurate enough that you could do the job.
I’ve never heard the Pioneer model you mentioned, as it has a tight on-ear fit designed for high isolation DJ use, and I don’t usually like the fit of on-ear headphones. Since I buy everything I review, I try to avoid stuff I think I might not enjoy unless I really want to go for it.
Pioneer does make some great headphones though. Their HRM-5 and HRM-6 models are tuned to a more modern, more neutral curve than the classic 770’s and their diffuse field response. And they don’t break the bank either!
A lot of this stuff comes down ultimately to personal preferences, even in the world of audio creation. I think as long as you’ve adjusted to your headphones and have a friend check your tracks on a different listening setup, you’ll do just fine!
