I was definitely talking about how DAW's handle
external midi in relation to its own audio tracks. So I am sorry for adding any confusion on the matter. The fact is there
is a difference in how various DAW's handle this and Studio One does it well so I am happy on that front. I have spent some time comparing how well some DAW's handle external midi while under pressure from the audio side of the program. And the reason is I still have external devices and they are powerful and I like using them. And most of the time the quality of the timing is independent of the rest of the show which is also something I prefer.
Now if the Op is talking about how any DAW is playing back a (fully quantised) midi sequence within itself feeding its own internal VST's then that becomes a more difficult thing to measure. And how DAW's are handling this is anyone's guess. The audio side of the program becomes involved so it adds to the complexity of it. So there may/or not be other differences compared to say what I was talking about.
There may be a way of getting several DAW's to playback a midi sequence
(complex ie fast 16th latin groove will put any system under test) and feed the exact VST in say all of them and record/export the results and compare. It may also be possible depending on how carefully you set the output of the VST involved to achieve a null between any two.
(mono recording and no effects applied) Then timing/groove shifts here and there would show up in poor null cancellation. Or even if the null thing did not work, if you panned two exports hard L and hard R you will also hear any tiny differences in the form of tight flamming etc. It is amazing what the ear will detect even with micro amounts of timing shift.
(for experienced drummers it is just how awkward the groove feels even if its only for a few beats or a bar or two) I dont think DAW's are applying any form of their own take on timing. That is not what is happening. They are all trying to play that sequence back the same way and in most cases they all will. The idea is to send those perfectly timed or quantised notes out at the same time to the VST involved so it can respond. I think if differences are felt it is due to the way they go about it and priorities, coding, etc...And if there can be differences in the way DAW's handle external midi then there possibly also implies there will be subtle differences in how DAW's will play back their own midi data completely internally and how it comes out.
What the OP should do is to get 3 or 4 DAW's all playing back the same sequence and get someone to blind test him and lets see if he can pick Logic's feel every time etc.. That really needs to be done to remove the bias while listening to the something in another DAW and imagining it sounds better. Although he may not identify Logic everytime it is possible to be able to pick the better feel everytime though. I can definitely hear how nice some DAW's can groove with external instruments with or without lots of audio activity going on. Midi and Audio are related and they are both often needed at the same time these days so the timing between audio and midi really does need to be factored in.