i use both, mostly BB but i have a few glass for the purposes of vacuum degassing when necessary...
BB clean easier than glass, easier to store, easier to handle, drop, kick, etc.
the advantage to me for glass is vacuum container, that is really about all they are useful for to me.
the unique disadvantages of glass far outweigh their benefits for me with the exception of vacuum. heavy, breakable, difficult to store, require care in handling, do not clean as easily, difficult (and dangerous) to handle when wet, and so on.
i can invert a BB with one hand and put on a Jet bottle washer attached to the sink, because the BB is hygroscopic nothing really sticks to it, some PBW to fully clean and then a little kmeta spray before plugging it ready for next use, i can stack these things on their side 100 high if i need to, they can topple down and make nothing but alot of noise.
as to their deflection when moving, i try not to move carboys if i can help it. when i do, i take the floater out of the 3-piece airlock so i don't have the issue of suction of airlock fluid into the wine. to me, it is not that big an issue.
but different people have different preferences.
IMHO, if your LHBS is only selling glass carboys, then they have an incomplete assortment of products and i probably would not patronize such a store with any frequency because they are likely ignoring other common products as well.
i dont use water bottles, one because i dont have any on-hand and two because i think BB is more refined solution.