Hello. Both remain great guns, but "best" would likely be a subjective decision...as most "gun decisions" wind up being.
The BHP has fewer internal parts than does the CZ and, in my opinion, the current internal firing pin safety on the HP does not mess up the trigger pull as much as does that on the "B" series of CZ 75/85/97s. I believe that the CZ85 "Combat" does not have the internal firing pin safety and as such doesn't have the "grit" associated right at the single-action break in the trigger pull.
I'm told that this varies quite a bit gun to gun, so it might be just a minor or non-problem or might need to be considered.
The CZ is not a clone of the HP, other than using Browning's locked breech design. It does not "bite" the hand that fires it as often as can the HP.
I have not noted any advantage or disadvantage to the internal vs external riding of the slide on the frame. The only downside might be that there's less slide to grasp when cycling the slide, but I've noted no real problems here.
Both guns have proven quite accurate in my experience as I own and shoot both quite a bit. Which is most accurate? I flat cannot tell as both can group better than I can with loads that they "like." I am very satisfied with both in terms of accuracy and reliability.
In holsters or aftermarket parts, the HP gets the nod, but original capacity magazines can be had for either (in 9mm) at rates less costly than some other "high caps."
My personal preference is for the HP, but others will disagree, some vehemently. I routinely remove the magazine disconnect and find that this simple alteration improves the trigger pull. In all of the CZs I've shot, the DA pull is long and smooth while the SA pull is kind of "mushy" compared to the more crisp HP's, but either can be shot well.
CZ's customer service is second to none and for the money, the CZ is very, very hard to beat.
The HP is a classic design and one that costs more since HPs are being imported in small trickles, but one that many do like, including me.
If you get the chance, handle both and decide; after all, yours is the decision that matters in this case.
Best.