A few thoughts:
The OP hasn't been back to comment on any of these topics.
Is there anything transcendent about shooting HKs? No, not really. They aren't designed much differently than many other Browning derived designs. Based on my experience they are very reliable guns that exhibit good defensive, and combat capabilities.
They are polymer framed guns so they are relatively light weight guns and in general, there are some examples that make excellent carry choices for civilians or for professionals. That's true of many brands. If you like the ergos, then it may be a good brand for a person to consider. If money is the concern then look to other brands.
It makes no sense to even bring up competition IMO or "shooting at a high level", which is rather vague wording. The OP didn't mention competition that I saw, and I can't fathom why someone would choose a relatively light weight polymer gun for that purpose anyway. A heavier all steel gun would be the way to go with a potentially longer barrel and sight radius. Personally I'd favor a Sig X-Five or Six for that purpose. Maybe a CZ, or a Beretta 92 brigadier model also.
If a person truly wanted an HK geared towards competition, a USP Expert, Elite, Mark 23, or the new VP9 LS would be a better choice I think.
You are going to pay a premium for a Sig or an HK, and both brands have good track records. Choose the one that feels best to you and you should be ok.