Anyone tried the Uppababy with a rumble seat?

[TribbleTuckandDismount]

As above, has anyone had any sucess with it?

Yes, I have had one, as have a couple of other people here. It's fab BUT you need the right age gap ie a baby over 3-6 months (ideally over 6 months) to go in the main seat, and the toddler needs to not nap (bolt upright seat that's makes a child's head loll if they sleep) and under I think it's 17.8kgs (?) which to be honest is a small time frame especially with a tall / big child. So better if you have a petite toddler. My toddler was too heavy at just over 3. Other than that it works well, is easy to use, easy to push, fab as an occasional seat kept in the basket ready to clip on, easy up kerbs and steps. There's photos and reviews here under the middle green button.