Cojoncio --
I can't comment on using VE Pro 5 with the external approach, but I did have problems with it also. To explain: as I introduced additional Event Input non-multi-timbral instruments in Logic (and thereafter set up External Instruments, after having set up other "multi-instruments" in the Environment), what I discovered was that Logic would NOT select the appropriate External instrument. For ease of discussion, I'll call this arrangement the "External Instrument Set Up." In other words, when SEVERAL Event Inputs were set up, Logic would select the MOST RECENT set of External Instruments, even though I had selected a track that contained an External Instrument associated with an EARLIER instance of the Event Input. Only the MOST RECENT External Instruments would be selected, regardless of the Track chosen in Logic. Put otherwise, when I selected EARLIER tracks with EARLIER Event Inputs, as I watched the Library to the right of the Arrange window, the correct External instrument was not being selected.
I CAN offer one suggestion that did help me however. After I had originally set up an External Instrument Set Up, I was having pops and crackles with the instruments that DID work, as well as significant LATENCY problems that I could NOT cure by increasing latency settings in logic and VE Pro. I DISCOVERED that I was using the WRONG network instance of my Slave computer. I do not know enough about network set ups to explain this, but when I tried to CONNECT the VE Pro 5 instrument to the Slave, I was given TWO choices, that is, TWO IP addresses (e.g., "10.0.1.9" and "169.255.43.102") for the SAME Slave computer. I tried an experiment. What I did was give the Slave computer a FIXED address, NOT using DHCP in the Network settings of System Preferences of the SLAVE computer. Thereafter, I selected the FIXED address for the Slave computer when I CONNECTED the VE Pro 5 instance in Logic, and the clicks and pops and latency issues, which you seem to be describing, disappeared! I have tried this on the simpler multi-timbral software instrument set up with equal success.
The folks at VSL are not in the business of teaching us how to set up networks, but it WOULD help, if they could provide a SIMPLE network setup involving one Mac Airport setup, one Master computer and one Slave computer. I think I have a typical OSX set up, with my Mac Airport for Internet access, my Master computer, and the Slave computer, ALL capable of providing DHCP service in their respective network settings. So, at one point, I had THREE DHCP servers going at once (I think). I believe that what DHCP does is provide IP addresses within a local network, so that the various computer members of that network can communicate via the address provided. Perhaps having THREE DHCPs turned on leads to confusion and latency issues I experienced. A user on another forum, who uses the Mac Mini in Logic as a Slave computer, suggested that I TURN OFF the WIFI network (the fan at the top the screen), so that the ONLY network the Mac Mini is communicating with is through the ETHERNET cable. Again, in the Slave Computer I opened up Network in System Preferences and assigned the Slave Computer a FIXED IP address, turning OFF DHCP.
All this said, I have NOT gone back to TEST the External Instrument Set Up, using my new network settings. At some point you like to get back to the music!
Hope this provides some help. I have tried to be REALLY clear in my explanation to help others who are not as far along in computer and Logic knowledge as you are. I have enough trust in this forum, that if I have made mistakes, they will be SWIFTLY corrected. :)
Steve