I wasn't so sure about it at first, but I really like the seed swap tool and think it would be nice to use it for the plant swap too. I noticed that almost all of us had done online seed-swapping, which meant we needed to spend less time seed-swapping after lunch and had more time to socialize.
It was also really nice to be able to click on a couple of links and see photos and lots of information about the plant for which seeds were available.
The only "con" I can think of is more a reflection of my tendency to procrastinate: I initially used "guesstimates" when it came to the number of seeds I had to offer because I hadn't actually divided the seeds into packets yet. It worked out, though!