You're probably playing above my level, so take this with a grain of salt, but a few ideas come to mind:
I think an important aspect of effective practice is to have a clear goal in mind. So if your practice feels a little ineffective, it could be related to the issue of not knowing where to go next. If you know what you want to achieve, it's easier to figure out a concrete goal to work towards, and how to get there.
A good goal is to go after what you feel weakest at. You feel your technique could use work? Maybe scales chords and arpeggios would be good for you, they're less controversial than hanon and it's easy to set goals with them... btw, conflicting ideas aside, the reason I like technical exercises is practical - not many performance opportunities so I'd rather work on exercises than pieces that I will forget before playing. If I was performing more, I'd do more repertoire. It's good to be practical.
on tds's suggestion, I've been working on a piece to record. I forgot how difficult it is to record a piece well! I get more nervous while recording than practicing, but I've found it's a good way to expose any slightly weak points in a piece. To make a good recording, the piece must be SOLID... Methinks this is a good thing to develop a high level of polish. Also will be nice to have a few files as a record of progess.
Another idea, to work on effective practicing: set little deadlines for yourself. See if you can learn a sonata in a week, maybe one that doesn't push the limit too hard. Maybe it wouldn't be realistic, I doubt I could learn a sonata in a week. But it would be a good challenge to examine and refine the practice habits.
I think a piece matures with time after we learn it, but I think I could get there quicker if I had better practice habits.