I think there is something else going on here and it has not been mentioned. It is not about timing resolution or quantising etc. And this is one of the more subtle aspects of DAW software but it still has the potential to effect some people. It is how well the DAW handles midi timing over the whole period and in relation to the audio side of the program and remember the audio side can include the metronome too.
I am a drummer of over 40 years and also have come from a large external midi system and being a drummer I am a bit sensitive to groove and feel of how parts play. And that is parts that are either live and not altered and quantised. I still produce a lot of sound externally at times and much of it can be very fast and percussive in nature so I like everything to groove and sit well naturally. Firstly I find that it all can be done.
I am running a Unitor 8 midi interface on the serial port and I am convinced it is one of the reasons I experience such tight and relentless midi timing on my system. I only have 8 serious hardware sound generators which means they have their own midi port. All 8 can sound a note at exactly at the same time if needed with none of them having to shift timing wise due to the midi serial nature of the signal. I often only ask one midi port to handle 1 to 2 midi channels which means very fast timing on each port still to hear 16 devices all playing back at once.
(my new Kurzweil PC3K is the fastest thing I have ever owned for how quickly something can make sound after receiving a note, it is ridiculous. All hardware synths vary with this and it needs to be tested and tracks adjusted accordingly) I also like tweaking the track settings for advancing or delaying some midi tracks in relation to others and the metronome too. How well does everything sit in relation to the metronome. And which metronome are we talking about too, Audio or Midi. They won't agree and one will need to be adjusted in relation to the other.
I believe different DAW's handle all this in different ways and I think there is truth in what the OP originally had to say. There is something else I am convinced of and that is how well a DAW handles all the midi timing over a long period in relation to the audio side of what is going on eg how well are those two things kept in sync? Yes they all feel a little different and I have been using Logic for many years and I can tell you that all the midi works nicely in that. Midi Audio relationship is good in Logic as well. Sonar is not high up on the list for me as to how it handles these things. I have found with 8.5 anyway that midi (even quantised) can get effected during heavy audio operations. Sonar was better for me when it was working with midi data only.
I am using Studio One now and it has relentless midi timing and feel and it all seems to rock on without being influenced by how hard the audio side is working. Somehow they keep everything in sync and over a long period too. There is even mention of its ability to record and playback midi very accurately something that is played in. If you can really groove with a live keyboard part I have found Studio One records all this and plays it back rather musically and never changes what was played in. Its gapless engine also allows perfect relentless looping without any glitches. I believe there may be something deeply embedded in the audio engine code that refers to timing and timing priority of audio and midi. It won't be possible to suddenly fix a non gapless engine either that I am sure of. It would have done by now.
It is one of the main reasons I use it because of the way it handles this and how it feels under pressure as well. Lot of things going on audio and midi all at the same time and how well everything relates to either the audio or the midi metronome. All tight and fast and feels good. It also has the ability to capture live loop recording while jumping midi tracks and adding in new material. You can go in and edit all the midi data all while the music plays without a hitch too which is fast and intuitive and bloody great!