FWIW - If mobility is an issue - Had a friend buy the Jet 15" bench-mount. He is a casual user. Works great. Put it on a rolling stand. I had wheels under my first floor-mount DP - "dicey" doesn't describe it.
The 6" quill is great. I did not have that first DP, but do now [old-arn Pm 1150A-VS] - can't do without it when you do need it, but not sure it is mission-critical.
The quill lock, though - as someone noted, that is essential, IMO:
> do the layout on the part[s]
> scratch awl point for bit location
> part under the DP head; lower the head and get the bit point in the target
> hold the head down, lock the quill.
> move the fence and rotate the part to get it all set up and locked down; clamp the part
> release the quill lock and make hole[s]
> I honestly don't now how else to efficiently, quickly, accurately hit the target dead-nuts first time, every time. No trials, no practices, no misses, - -- very fast.
On the Forstner bits - my take is that 28 sizes is beyond the pale - no clue what to do with all of those sizes. I have the basic 7-pc set. All I need, except the time I rebuilt a kitchen and needed a 32mm. It is somewhere in a drawer I think.
I had some junk brand to start. Then, went with Famag. Then, Colt. Use Famag as my daily driver, and the Colts come out when there is something special going on. But - to be honest - I like them both equally well.
Last - I find that I chuck up brad point bits more often than the Forstner, FWIW. I really like the LV HSS bits - I think I bought a set, and filled in some slots - - - looks like 11 dia total in the drawer/holder.
When I started woodworking, I didn't know squat. I have progressed in 30 years - now I do know squat.