Congrats dude, it's great what you've done!
If you ever start feeling the need for more speed, consider any kind of clip/strap-in pedals, higher pressure tyres and a thinner seat as GenKreton said.
You'll see a huge improvement in FE (Food Efficiency) riding clipped-in. Using muscles in the back of your legs on the up-stroke is when you'll really notice the benefit of a narrow seat.
I don't agree with having 50% of your weight on your arms, even on a dropbar roadie.
Elite cyclists might look like they have weight on their arms, but they definitely don't. You might have force through the bars pushing & pulling as part of your stroke (especially without clips), but never supporting your body weight. Plenty of info on the interwebs under "cycling posture" and such.