I don't know if this has anything to do with a better radio since the update or not, but i had LTE (a signal of -109 IIRC on band 26) in my apartment yesterday. I usually get LTE in the parking lot but drop to 3G in the building. Again, I don't know if it's an updated radio or ongoing optimization of the network since they're still in the process of getting B26 live in my area.
My biggest concern with any OS update is battery life. I'm always worried it'll be decreased with an update (even with Google saying Lollipop extends battery life). With yesterday being an unusal usage day for me with the update taking a half hour to download on LTE and the screen staying on throughout the installation process, today's going to be the first time I'll get a real look at battery life on 5.0. Hopefully Google's claims of longer battery life are true, even though I'm already able to get through a full day without a problem on most days.