it was hard for me to use the new version.....to see the attachments directly on the e-mail it doesn't seems a good idea...
First off, Thanks for taking sometime to try the new experience and for providing feedback.
You mention that things feel a bit too cluttered on a laptop.
Can you try disabling these two settings and see if it feels better.
Click the Gear in the top right, and then disable Sender Photos and Attachment Previews.
Hope this helps!