Has anyone taken the Trenitalia train Zurich to Milan

If you want to get from Zurich to Milan, its the way to go. What questions do you have? Its just a train.

Scenic? Pleasant? Recommend stops?

A 35 mile tunnel completely under the Alps makes for a speedy trip although somewhat lacking in scenery. If you want a scenic trip, take the Treno Gottardo with a connection in Bellinzona taking another 1 1/2 hours.

Have not gone on that route but are considering it for a trip in September. Have you considered Bernina Express or Regional trains along that route? Man in seat 61 (www.seat61.com) referencing Bernina Express. There is a video. Seems scenic. Maybe others can comment.

This unlocked NYT article describes the Treno Gottardo in the 2nd of 5 train rides listed.

https://www.nytimes.com/2025/03/26/travel/train-routes-europe.html?unlocked_article_code=1.7E4.NAWO.B2FjR3vEbEBi&smid=url-share

We’re thinking of taking the Trenitalia train from Zurich to Milan

There actually is no Trenitalia train from Zurich to Milan. Trenitalia does not operate trains in Switzerland. The trains on the Zurich - Milan route are operated by SBB till Chiasso, where Trenitalia takes over. Most services are run with SBB Giruno Trainsets.

But you are better of to book this with Trenitalia, as there you can pick your seats, whereas on SBB they are automatically assigned. The train is nice, modern, and the ride is pleasant. Basically just a standard fast intercity service.

If you want scenery, take the route via the Treno Gottardo. That you would have to book on SBB though, as you cannot book that via Trenitalia. To book that route on SBB enter "Gösschenen" as a VIA.

Also the ordinary fast train via the deep 35 miles tunnel is somewhat scenic, as on both approaches the railway line coasts around lakes and pre-Alps landscape.
The scenery along the old Gotthard line (Treno Gottardo) is nice mountain scenery, it becomes much more interesting if you know how the line was designed. Some tunnels are helicoidal, that is in corkscrew form, you do not perceive the curve and the ascent but basically in a few minutes you are left where you were but on a higher level. On the north approach this is why you pass by the Wassen church three times at different levels (but if you do not know, they are just glimpses); on the south ramp you could see from the top level of Biaschina rock your very same railway line on two different lower levels. It is the Louvre museum of the railway enthusiast, but maybe if you do not share the enthusiasm the faster line is just as good.
The Bernina itinerary, so often cited here, is a different kind of railway; not built to sustain intense traffic, still a sort a miracle they could build so high a railway without rack or switchback sections, incredible landscapes but very slow; built to keep together different pieces of Switzerland, it arrives in Tirano, italy, that is nowhere close to a transportation hub.

You do not say when this is to take place. Keep in mind that if you take the Bernina route, it looks like there will be track work this summer on the Tirano-Milan rail line beginning mid June. So part of the way will be by train replacement bus.

We will be traveling this October. We won’t take the Bernini Express because I travel in a wheelchair and Trenitalia provides individualized lift service to get on and off the train.