(1) The trailgator: http://www.trail-gator.com/
We never used it. Eventually, I gave it to the neighbors. I'll let you know if they ever give me an opinion of it.
(2) Moederfietsen: the Townie with Bobikes fore and aft and a front tray
I love the Townie. R. hates the Townie seat, so he got a Brooks leather seat (whatever the canonical one is; I've forgotten the model number). The Brooks leather seat is okay. A few weeks ago, after not even once getting on the bike to ride it, he switched it back. [Correction: He did ride it with the leather seat earlier in the summer, but hadn't ridden it for a long time.] Of course, he then wound up riding the Townie somewhere. Predictable. I LOVE the Townie seat. I sort of wish R. would undo whatever the hell he did to the handlebars when he switched the seat around, but it's not worth an argument. T. can undo the Bobike buckle, but so far has been willing to stay put in the seat when riding. A cargo net keeps his Kettler balance bike on the front tray when we've been out playing and he's tired and wants a ride home. Do not attempt this without practice -- keeping that bike balanced on the tray is very, very tricky. We have a Bobike mini mount in front, and I've taken A. to Benjarong for takeout many times; the bag goes nicely on the front tray under the net. I don't think I've successfully had both kids on the bike at the same time. The downer here is you can't have the Maxi and a rear rack, but the front tray is adequate, once you get used to managing the awkwardness.
I wish I had gotten lights put on. Probably next year. The Townie bell I bought as an accessory has a good sound to it, and the Townie cupholder works okay.
It was a huge pain getting the Bobike Maxi on the Townie and required more than one consultation between the bike shop in Portland that sells the Bobikes, and Belmont Wheelworks, which did the work. Many thanks to all of them for making this happen.
I also had a frame lock put on this bike (an Axa, maybe a defender?) which I love, but cannot vouch for how effective it is because we live in a town where people routinely leave unlocked bikes lying around. I also had a better kickstand (a Hebie) put on this bike. I wish kickstands worked miracles but they do not. However, the Hebie is pretty close, as long as the bike isn't tilted and weighted. So be careful out there.
The bar end mirror installed on the Townie is basically useless, because the angle doesn't work quite right and is not adjustable (at least not for me).
(3) Moederfietsen: the Bianchi with Bobike mini in front, and a Moose Rack for a Kazoo behind
This is the ride-to-school bike. R. brings T. in in the morning; I pick up T. in the afternoon. The Moose Rack permits some panniers while the Kazoo is in use; I'm using Avenir Metro 2.0 grocery shoppers. They are open baskets, which so far is okay, but might become a problem if we are serious about doing this in crappy weather. I'm betting we're not that serious. The lighting system is fantastic -- I could not love it more. I have on occasion used it when getting takeout, and at least once on a very late group ride with T. and his grandma. I had Belmont Wheelworks put together a front wheel with a dynamo to power a Busch & Miller Lumotec IQ Cyo, IIRC (http://www.peterwhitecycles.com/schmidt-headlights.asp#lumotec). My rear red flasher is the one I've always had, integral to the seat that comes standard on my bike. R. and I have each, on occasion, had both kids on this bike. I've taken T. on the trailabike to the store and gone grocery shopping. Everyone loves this bike. We get compliments every time we take it out.
The Bianchi also has a Hebie and an Axa and we love them on this bike as well.
The big thing I'm working on right now is trying to weatherize us. It turns out that below 40 degrees is kinda brutal when you're riding on a bike at a leisurely pace. It was tough to get enough clothes on me. I got a new winter coat (a Columbia 3-in-1 Bugaboo) which has appropriate seams and windproofing and a pair of ski pants. I'll need to get T. something for his legs and he'll need the next size up puffy coat at some point. If only we could keep mittens or gloves on him.
I'm also contemplating the Bobike mini wind screen and plastic bubble thing [ETA: Just the windscreen. I ordered it from Longleaf this time, and pre-emptively got the extender, because if I know my Townie, I'm going to need it.]. I wonder just how committed to this I really am. It really sucks pushing a stroller, after getting used to pedaling, but maybe it's time to suck it up and start using a bike trailer instead. We've got the stroller kit for the Burley, which means I could be a _really_ lazy parent.