I can't add much to the discussion but I will say that your speeds are similar to mine when my 4G LTE (VZW) has 4 bars showing (Columbus, OH). I've had the speeds go to double that (and approaching triple that), but yours are very close to mine on a consistent basis, and most of the time when I've tested I've had at least 4 and sometimes 5 bars.
I'm not sure how much of an effect the number of bars has on actual DL and UL speeds, though. I've always assumed that the more bars showing, the better the reception and hence the better the speeds. However, while doing some rooting around on the interwebz I've read some things that lead me to question my initial assumption. I'm sure there are some people on this forum who can shed some light on the relationship between signal strength and speeds.