Pick up the Trek and step on your bathroom scale; that will give the approximate weight (subtract your own weight from that number).
Co-Mos weigh in at about 37 lbs, all the way down to 29.4 lbs for the lighter/$$ models.
Prices is higher, but so is the quality.
Have put 58,000+ miles on a custom Co-Motion . . . well worth the $$.
Keep your eyes open for a used one to save some $$.
Yes Co-Mos are better than any Trek. Yes, they handle 'almost' as well as a roadbike.
Have ridden over 30 brands/models (includingTrek) of 2-seaters.
In the end U-2 and your budget will decide; hope this is of some help.
Pedal on TWOgether!
Rudy and Kay/zonatandem