Long time lurker here.
I have been looking around on Head-Fi and a bunch of other audio sites, and still can not make a decision on this matter. Currently I have the M50s, the Koss Portapros, the Klipsch Image S4s, and a Fiio E5 with an L3 LOD. I use all of my headphones and use the E5 when I can. The only time I can use the LOD is when I use my 4GB iPod Nano 2g, which is becoming far too restrictive (I plan on finding a 5th gen Classic, though) and I end up using the E5 straight out of a computer 3.5 mm jack.
Trouble is, I hate IEMs but have to use them anyway. I find them really uncomfortable, they get dirty, people want to put them in their nasty ears, I have to keep my ears super clean, and they break despite the fact that I baby them. They are not for me. However, I use them all the time when I'm outside working, mowing grass, or at school. Some of the time I can use the Portapros, but they are open so mowing the lawn with them is no good. I'm also not a fan of leakage.
For headphones, I'm looking at the Sennheiser HD 25-1 IIs. From what I gather, It's really hard to go wrong with them. Even though there might be no SQ improvement from the M50s to the HD 25s, I think they would be a good buy since they fit my needs. I'm not totally sold on them, so tell me if you have something better in mind for me. I would be willing to spend $175 on headphones, $200 as a stretch.
Here is where I'm stumped, though. I want a portable amp/DAC that will last me a long time. When I can afford them, I plan on getting some HD 650s or Beyerdynamic DT990 600 ohms. I want to be able to use the amp with the LOD when I have to but still be able to use a USB DAC when I listen from a computer. Having the amp and DAC separate, like the iBasso DB2 Boomslang and the PB1 Toucan together, is not a problem.
I've looked at units from RSA, iBasso, Fiio, and a few more I can't remember. I don't want an E7 since the amp is essentially an E5. I hear the DAC is great, but the amp won't be good for when I move on to higher-end cans and want the portability that the E9 add-on does not have. I was seriously considering the iBasso D12 Anaconda or the D2+ Boa, but then I heard they weren't so great in terms of bang-for-buck.
Since my first world problem involves portable cans, full-size cans, and portable amps/DACs, I was unsure where to post this. I think this might be my best bet, though.
Anyone have suggestions for me? Thanks!