Bottle cages!
I use the same cage on all my bikes, the Bontrager carbon SL has been faultless. However I needed another cage on the hurry up. So whilst placing an order I bought a Tacx jobbie thinking a Taxc would be okay.
First outing the bottle fell out on the road, and looked like it would fall out on any mildly bumpy road. I put up with it.
Next time I tried bottles in it and used the one that fitted the best. During the ride it was pointed out that my bottle wasn’t in properly, all day it kept trying to come out.
Turns out that there is no side support. In fact you can tilt a bottle in the cage and almost pull it out from the bottom.
Anyway, it’s not the cost or hassle, but when someone designs these things do they ever actually try them out and then think whoa this is rubbish?