OP, out of anybody's advice on this website, i would take yooper's into consideration most. every time she's given me advice, it's been spot on to what i've later found through reading homebrewing books and articles (not that i didn't trust her advice the first time, just that i usually only ask for advice on here when i'm in a pinch and don't have time to scour through all the resources. then when i do have time, i realize she was spot on.)
honestly, and i suppose i'm probably just reiterating what others have said, if you're getting off flavors with your diipas, i would seriously consider checking your pitching rates and ferment temps. i don't do ipas under 7%, and have never had a problem with off flavors. the last one i brewed could've been either considered at the very high end of an ipa, or the very low end of a diipa, and it was great at the 5 week mark (2 weeks ferment, 3 weeks bottle). but again if you're kegging you could be enjoying much sooner. with that one in particular i found that the perceived bitterness actually went up as time went on (i assume it was as the malts melded a bit more) but the strong hops flavor and especially the aroma started to fade significantly after the 6-7 week mark.
honestly, and i suppose i'm probably just reiterating what others have said, if you're getting off flavors with your diipas, i would seriously consider checking your pitching rates and ferment temps. i don't do ipas under 7%, and have never had a problem with off flavors. the last one i brewed could've been either considered at the very high end of an ipa, or the very low end of a diipa, and it was great at the 5 week mark (2 weeks ferment, 3 weeks bottle). but again if you're kegging you could be enjoying much sooner. with that one in particular i found that the perceived bitterness actually went up as time went on (i assume it was as the malts melded a bit more) but the strong hops flavor and especially the aroma started to fade significantly after the 6-7 week mark.