I own the JVC's and Sony's. The JVC's sound better overall, and have a more mid-bass punch to them. The XB-500's have gobs of bass and sub-bass for sure, but the mids and hi's will need some EQ-ing imho. If you're not afraid to EQ both work very well. The JVC's are bigger, tougher built but less comfortable. The XB-500's are lighter and more comfy, but have a shorter and chincy cable. I am not familiar with the Sens HD212.
But if you want mostly bass...the XB500's. If you want more overall sound, do the HARX700 imho. Either are true closed, the JVC has a ring port and the XB-500 have small bass ports so both will leak a little but neither is all that bad. As an owner of both they get used by the family while I have moved up to my Hifiman HE-400's and I also havce some Denon D2000 (If you want bass and great sound from a super comfy and easy to drive pair of headphones...these are it imho. Just be careful of the hinges!). I prefer my HE-400's but I realize that's way out of budget for most...and still question how I spent so much sometimes! But then I hear them and with the D2000 earpads they sound amazing! They don't have the gobs of bass the XB-500's or D2000's can produce, but the range is there, it's very present and it all works together so well.
But going to your choices, it just depends on what you want and what you can or can't deal with. There are a lot of options out there, but I will say the two you have chosen are decent choices if you want a pure bass experience, and not necessarily clean bass just quanitity...the XB-500's are your choice. Them and the 700's can be EQ'd to sound pretty good overall depending on what you're seeking. Grab a pair and enjoy! :)