I cannot fully agree on this.
There is tagged and untagged traffic, so that has nothing to do with the port type (hybrid/trunk), so communication between a procurve and h3c should just work, with hybrid or trunk port (or must be config mistake).
Essentially, the hybrid port allows everything from the trunk port, plus : it allows more control over the untagged traffic.
If you do not need this control, you can go for the trunk port.
In my installations the rule is simple:
* uplink (switch) ports : trunks
* user/end-node ports : hybrid
This makes it very simple to distinguish the uplinks to other switches (display port trunk) from the downlink ports to end-points which are vlan-aware (dis port hybrid).
The added value for hybrid on untagged is :
* instead of port-based packet processing (port config PVID will decide to which vlan the incoming untagged packets are assigned), the hybrid port supports packet-based vlan processing (based on the values in the incoming ethernet packet).
You could compare it with a tagged link, which is also packet-based vlan processing, but in that case, the switch will read the 802.1q tag value, and use that value to assign the packet to a vlan.
With a hybrid port it is the same, but you just change the relation : the switch can read e.g. the source mac address value of a frame, and assign it to vlan x for maca, vlan y for macb.
This sounds complicated, and it is for manual config examples. You could configure for instance a rule so all untagged packets from mac 123456000000 mask ffffff000000 (some printer range) would be assigned to vlan x (the printers vlan), so the packets which are tx on an uplink will be tagged with vlan x. All other untagged packets would not match the rule, so they would be assigned to the PVID vlan configuration.
Essentially, when no rules are defined, all traffic is assigned to the PVID (just like a trunk interface).
The power comes when this concept is combined with edge-authentication.
When you enable 802.1x or mac-auth on the port, you can use a central vlan assignment via radius. The first device online (assume macA) could be assigned to vlan 11. On a traditional port, the untagged port membership changes, so when a second device (macB) comes online and would be assigned to vlan12 by the radius, it cannot come online since the port is already untagged in vlan 11.
Now with the hybrid port, the switch can program the port with the learned first macA and assign it to vlan 11 (better than the manual config!), so when the second device with macB comes online, it programs this macB into vlan 12, and both hosts are online, untagged, on the same port, while they each belong to their own vlan (e.g. dhcp request from macA would be tagged with vlan 11 on uplink, macB with vlan12 on uplink).
This means when an unmanaged switch with 2 internal hosts (like meeting room) would be connected to the hybrid port, 2 internal hosts can be authenticated and assigned to their own vlan at the same point in time.
You could even have a 3th host which fails authentication, so it would be assigned to the guest vlan on the same port.
If you do not need this functionality, a trunk port will do fine as well.
Best regards,Peter