So, i have 115gr Corbon DPX 9mm+P and Speer Gold Dot 115gr+P+ LE only ammo, and i'm having a hard time deciding which to use in my HK P7.

Corbon DPX: 1250fps, 399fpe
Speer Gold Dot +P+: 1300fps, 432fpe

I like the Barnes TAC XP bullet used in the DPX better, but the Gold Dot is LE only ammo, and made to extremely high QC standards. And while not a solid copper slug, it is still a bonded core design. The one area where there is a clear difference between the 2 is in bare gel penetration. The 115+P+ Gold Dot only penetrates 10.5" (The DPX is in the 12.5" range)....but opens to .83" diameter (Source: Speer ammo poster). The Speer round also has nickel plated casings.

I'm leaning toward the Gold Dot due to the superior QC and nickel plated case.

Both shoot equally well in my gun. The DPX has slightly less recoil than the Gold Dot +P+ round.