I figured it made sense for me to circle back with BF and post a review on the Joule 2.0. Fair warning: I'm a techno geek, at work and at play, and have the disposable income to adorn our bike with toys.
We now own two Joule 2.0s, and they ride our tandem alongside a Garmin 705 (for me) and a Garmin 800 (for her). We have dual, independent Quarq powermeters on our tandem, so we picked up the Joules to help us see real-time stats on our efforts. The Joule presents numbers in a distinctly different manner than some bike computers, though perhaps there's a parallel to others where you can have speed or cadence in big font, and (everything but speed/cadence) in small font. The Joule lets you put six categories (where "category" is a "triplet" of variables, such as speed/average speed/max speed) on the six upper fields; as you move the joystick, the "cursor" jumps between these six fields, and for whichever category it's on, the other two variables of the triplet show in the bottom two fields. In a sense, you can pick eighteen variables, and see eight at a time.
Another feature that I really like is the software graph of the rides: as you come home with ride data, the software gathers your peak 5-second, 30-second, 2-minute, etc. power levels for the ride, and displays these numbers as a graph. Meanwhile, it's building a history of all of your tracked rides, and shows another line on the graph representing your best numbers ever for each of those time windows. By looking at the graph, you can instantly see how you did compared to your history. For me, I have strong legs but a relatively weak cardiovascular system; I can hit 1200W but have absolutely no ability to sustain more than 250W, if that. Lately, I've been better at not spiking my power, and sustaining it longer but lower, so I'm slowly bumping up the longer intervals while staying well under my shorter peaks.
I haven't been impressed with the battery life, especially when the unit is sitting "asleep". Two weeks of idle time after a charge can result in a half-charged battery, I think.
It's overpriced like everything else, but I find the manner of the display quite useful, the ability to see my IF (Intensity Factor), TSS, and various peak power levels on the screen to be worthwhile, particularly when combined with the historical graph. I did pick them up for <$300 by using Google marketplace or whatever it's called.
I suspect the Edge software upgrade brings the Edge essentially to parity with the Joule. I wasn't able to find the facts for that upgrade when I was considering the Joule; at the moment, I can't find any release notes on their site, and the owners manual link shows nothing of the IF/TSS/NP fields.
Yes, it's four cyclocomputers on one bike. Do realize that it's a tandem bike with two sets of eyeballs and two power meters, so the intention is for either rider to manage their own training and be able to assist the other. With today's crop of cyclocomputers only able to listen to one power meter at a time, this meant four CCs. If Quarq were to finally release their Qranium, life might be different.