As a long time lurker on this forum, I'd like to thank everyone for their recommendations on the tenore. They're an amazing pair of IEMs for the price, and sound comparable to or better than my other way more expensive IEMs.
I have 2 pairs of tenores, one of which I believe to be reference, and one which is bass heavy. My first pair I received were bass heavy (after comparing to impressions on this thread and my own pair of er4s) so I duly ordered another pair from amazon japan (which was easy since I'm based here). The 2nd pair I received has a much more balanced low end and they sound amazing to me with sony hybrid tips.
I read something regarding wire lengths earlier, and after comparing both pairs, the bass heavy pair has a wire length that is about 3cm longer than the reference pair. This difference is probably due to manufacturing variations from batch to batch, which might explain the variations in bass levels.
That being said, both pairs still sound darn good and I will be keeping both.