Had an opportunity to fly on a E-170 (US) and I was very impressed. This is by far a more comfortable aircraft then your traditional RJs. Bombardier has a lame duck in their 70-90 seat offering. PS. I would not consider this aircraft a regional jet, it felt alot more like your traditional 120-150 a/c. I believe this (the E-190) will be a BIG, BIG winner for JB and I hope to see it at RDU ASAP.
But as far as spare parts/commonality, pilot flexibility, traing time and materials, aircraft mechanic problem recognition, and aircraft price discount, I would think that Jetblue would be better off with the A318. Just my thoughts.........
We have the 318's at F9 and there are many system differences that would add parts costs to your inventory. Most of the flight computers, ACSC systems, SDC system, and the CIDS would all require different parts than the 319/320. Don't know if you have received the new LCD's on any of the JB Airbus's, the newer 318/319/320's have these displays.
One problem we face in DEN is that the 318's tail is approximately 2ft longer than the 319/320, so it can't be driven under the A concourse bridge. So we are forever cursed to park these aircraft on the north/west side of A concourse ONLY!
I'm not an aeronautical engineer but as I recall there is some reason the tail has to be bigger on the shrunk plane--adding to weight, which is why the 318 weighed 10 tons more than the 190. Think what a year of dragging that around would cost at $1.40 for a gallon of jetfuel!
While thos aspects do add cost, because of the size of the order B6 placed, you gain significant economies of scale. For example, even if they bought 318's, B6 has to order tires for all the airplanes they have. Because the 190 fleet will be sizable in a short period, the price of tires, on the aggregate will be approx. the same as if they bought 318's. While this is a general exmple, this is how a typical fleet planning group looks at this decision.
As for problem recognition, I think it is fair to say that won't be a problem. As is seen at all of the legacy carriers, mechanics can work on multiple types of aircraft. On top of that, the use of manuals, etc. is encouraged, thus making it less of an issue.