The Marquis is basically a Veritas plus. A few on here will praise it and advise you to get one. i'm going by, relative, ease of use striaght off the shelf.
I'll assume you've watched and read all the reviews or each so it will come down to personal preference and budget. Lke most other things in life.
I'm looking at the Vertex and the only down I can see to it is the teensy wee holes in the -ve posts, not a deal breaker really, but..... The Airflow does looking interesting tho'.
I recently reacquired a Veritas in trade, the first one I had was a crappy shitebag off of fasttech and it was so bad I cursed it to Hades and back. However, now that what I have is decent, it isn't as bad as I thought and the deeper juice well is a plus in the car.
Search thro' the threads on here for each, and there are a few, you should get a longer term view of each.
Sorry I'm no really helping at all, just chuntering crap whilst I wait for my lunch too cool and coffee to brew.