I wrote a blog post last year about loom length and how it impacts tapestry weaving. The post is called Questions from the Book: Ease of Weaving and Loom Length. In that post I advocated for longer looms and more free warp because it really makes weaving easier no matter what loom you’re using. See the post for details about why I feel this way.
Since that post, the one Mirrix loom that I have struggled with a bit because it felt like the warp was too short has had an upgrade. (Admittedly this is just my preference and the original Little Guy loom works just perfectly as it is!) You can now get the Little Guy loom in the Tall Guy version. The new loom adds inches to both the threaded rod and the copper pipe making the overall maximum height of the loom 5 inches longer.