In our house we call the E190 our "Baby Plane". Since Aug 29 Mrs T and I have used them twice. We always travel with rollaways and outbound I packed my bag and "had" to use the extender on my case. On board, it just didn't fit and I had to check it. This was handled efficiently by our cc member. Inbound, Mrs T packed my bag and the extender was not necessary and it fit perfectly! Go figure. We were in Economy.
(In hindsight, when I checked it, I should have asked the crew to treat it as as a stroller and have it returned to the aircraft door upon arrival.)