My first Delta A220 (or C Series if you are old school) showed up in this post from when I was at DFW.  It was only on the ramp so no flying action on that occasion.  SeaTac is one of the regular destinations now and one was departing when I had just landed and was waiting to meet my sister off her flight from the UK.  Shooting through the windows at an airport is a bit hit or miss.  The quality of the glass is one concern since it is thick stuff.  You also have mixed cleanliness and reflections from the interior.  Then you have to deal with the heat coming off whatever is on the ramp with the potential for lots of APU and engine exhausts.  However, I did get some clear shots of it as it got airborne.  I think the shape is quite distinctive and I am really coming to like the type.