Yes, coding for ItemChanged event is simpler.
Using MultipleItemsChanged is a bit more efficient - but not too much. The savings are in the fact that just one event is fired if there are lots of changes coming in. You still need, however, to access the details of each event by calling into the component, causing number of round-trips - so the performance savings are not big.

The VB6 example project is attached.
SubscribeMultipleItems.zip
You need to reference "OPC Labs EasyOPC Type Library":
1.png
The actual code looks like this:

Dim WithEvents easyDAClient As easyDAClient

Private Sub Form_Load()
Set easyDAClient = New easyDAClient
easyDAClient.SubscribeMultipleItems _
"", _
"OPCLabs.KitServer.2", _
Array("Simulation.Random", "Trends.Ramp (1 min)", "Trends.Sine (1 min)", "Simulation.Register_I4"), _
1000
End Sub
Private Sub Form_Unload(Cancel As Integer)
easyDAClient.UnsubscribeAllItems
Set easyDAClient = Nothing
End Sub
Private Sub easyDAClient_ItemChanged(ByVal varSender As Variant, ByVal varE As Variant)
Dim eventArgs As EasyDAItemChangedEventArgs
Set eventArgs = varE

List1.AddItem eventArgs.ItemDescriptor.ItemId & ": " & eventArgs.Vtq.ToString()
End Sub

And here is a display from sample run:
2.png
I hope this helps.

Hello.
I will prepare it; should be today or by tomorrow.
Best regards
Zbynek Zahradnik