Hi Zombi, You didn't give us a ton of information like how long the bike was sitting, was there crap in the fluid when you bled the system etc. If the pads look normal (not new just like old pads) then as long as they don't have brake fluid, fork oil or the like from a leaking seal I suspect that your problem is not the pads. Contaminated fluid and/or just sitting will often cause the pistons to stick in either the calipers or mastercylinder. What I would do is flush your system (both front and rear) with alcohol (not 70% or 80% but 99% alcohol not the stuff you get from the local drug store but pure ) and then bleed the system two times with brake fluid. Try that and see if you get better lever and pedal feel. If that still leaves you with trouble then you may need to rebuild the system. This is an easy task but do take the system apart before ordering your kits as you may need to replace caliper pistons (most mastercylinder kits come with a piston and seals) as most often these are steel and corrode. Also remember that if the bores are scored then you'll need to replace the calipers/master. I get my stuff from a firm called Brakecrafters as they have a good stock and fast turn around time. Also do use good brake fluid like Motul 660/660 or AP 550 not some DOT 4 from your local discount auto parts store. There's a huge difference and the cost is well worth the results.So I have been out on the 2014 Duke a few times. Changed all the fluids bled the brake system no air. What I am finding is I seem to have to death grip for a quick stop and the performance is still poor with crap feel. I am beginning to think the pad compound had changed and is not as efficient. Is this a thing or should I be posting in LoonyToons.
One last thing to not forget brake fluid is hydroscopic. It absorbs water like crazy so at the very least add some plastic wrap top the container top if you have some left over. Myself when I'm done with the last brake bleed I throw away what's left. Again have fun brake systems are for the most part simple and an easy repair.