Mainly an electronic listener here. Big house/techno head with some DnB and trance tossed in the mix. Also a DI listener. I dislike the HD598 for electronic music. I find them boring and unengaging. They're also open, so not sure if that's a concern for you in the office.
The DT770 has a rather apparent emphasis on bass with big impact and maybe lacking a bit in the detail department. They're is also a slight emphasis in the highs, leaving the mids a touch recessed. These are decent for electronic I find, but I much prefer a can with more detailed/textured/exciting mids. For the price though it's not a bad pickup, plus they seal relatively well for an office environment.
For purely an electronic can around this price range, the HE400 (open) would probably be the way to go. The bass is very detailed and extended, the mids are wonderful, the treble is detailed although can be a bit sizzle-y at times. These are not neutral cans and have a more "fun" sound signature. I do not prefer these with hip hop though as voices can sometimes have a weird presentation. It's not necessarily bad, I just prefer other cans for hip hop.
For a can that can handle both hip hop and electronic I would suggest either the AKG Q701 (open) or the Mr. Speakers Mad Dog (closed). The AKG is very detailed for it's price and also has a very "real" or natural presentation. The sound stage is incredible as well which makes for a great electronic can. The bass doesn't dig as low as the planars, nor do I find the bass to be as detailed, but it's still very enjoyable. They have awesome mids and I think it's where this can really shines. These are a big closer to neutral but I think they're a touch on the warm side.
The Mad Dog is a closed planar with great, lush, silky smooth mids, very clean and detailed bass which can sometimes lack impact, and laid back highs which are still detailed but never fatiguing. The Mad Dog also makes for a great hip hop can. These have a relatively dark presentation but are also fairly neutral.
All of these headphones will definitely benefit from a good, powerful amp and a dac. If you don't have one already, you might want to price that into your budget. When you start moving into this price range of headphones, most of them tend to like a little bit more power to sound their best. Keep in mind that DI.fm premium streams at 256mp3/128aac. All of these cans will improve with better source material but the premium streams still sound good and a headphone upgrade will improve your listening experience.
I own and love all 3 of the aforementioned headphones for electronic music in their own way. I don't own the HD598 nor the DT770 but I have spent considerable time with both cans.