When considering the bench mount types it's probably fair to say that the round column machines are best thought of as drill / mills leaving the dovetail column breed as mill / drills.  Fundamental problem with the round column breed is that moving the head up and down without loss of angular registration is impossible in standard form with virtually all makes.  The old Naerock machines had a registration key which I believe was quite accurate but generally you will need to devise your own or copy one of the many published methods if such registration is important.  The big disadvantage is that you have to set-up so as to have both sufficient daylight between chuck, collet or end mill holder and work to handle tool changes yet be able to cover the depth of cut needed with the available quill travel.  Depending on the size and type of work envisaged this varies from irritating to toys out of pram time.  Its a great help if the job is small enough to crank out of the way when tool changing.  Inevitably you end up working with a good deal of quill extension a lot of the time.  Generally considered not ideal practice as it reduces rigidity whatever the machine and a small, economically priced home shop machine will be less rigid to start with.  The dovetail column type does allow you to move the head up and down at will and tend to be more rigid so comparatively speaking its a win-win.

I had a Chester Lux style machine with R8 taper spindle before moving up to a Bridgeport.  It was happy to take as heavy a cut as I'm prepared to use on the Bridgeport, mainly because there is a limit to how much swarf flying about I can put up with.   Major disadvantages was the poor visibility past the big square head and the limited table size and traverse which made setting up and seeing what was going on harder.  I had a fair few "Cheapy Chinee" issues to sort and was very glad I fitted a proper glass scale DRO set immediately as there were some deeply buried problems of the "I don't believe this!" type leading to inconsistent results if working off the dials.  The fundamental accuracy of the machine was excellent so it was a shame that assembly QC problems let it down.  I gather this sort of thing is not the major issue it was a dozen years or so back.

In my view, especially if you intend to work in 12" to the foot scale, there are too many compromises involved in hitting the under £1,000 price point to get a truly all round satisfactory machine.  Its easy to forget just how much machine you get for your money and have unreasonable expectations.  Which doesn't make it impossible to find a machine where the compromises are nicely tucked away in areas which are of no consequence to you.  You just have to think carefully about what you want and look closely.  If you expect to do much milling I think the knee type "2/3 rd of a Bridgeport" style will be more satisfactory overall.  But at getting on for twice as much money they darn well ought to be.  Don't forget cutting tool, tool holding and work holding costs.  Say £200 to £500.  Scrimping, cutting corners and making do with what just about works (after fettling) makes for a miserable shop experience.  I don't dare reflect on the amount of time and money I've wasted over the years being penny wise but pound foolish.

Clive

I have to agree with the guys  above, a drill/mill is not a milling machine.  I've been using one for ages, and until I get my second Haighton Mill finished it'll have to do any little milling jobs I need.

I have a Nutool version of the RF30 round post, which is the larger of the two common designs, with a lot of modifications to overcome it's weaknesses (it 's been an on-going and rather fun project for me) ;  roller nuts fix the dreadful backlash in the table screws, a wishbone fixes the head movement problem.

If  you are buying new then I would not recommend a round post drill/mill (or even the dovetail types for that matter) - for that kind of money you could pick up a used  small-ish knee mill (e.g. one of the Bridgeport* replicas ) with tooling . If you come across one cheap in need of some work, then they are a handy machine if you have the space for it, and a mill.

* IMO Bridgeports, like Myfords and 'Designer' branded goods, tend to be over-valued  - there are plenty of other machines that do as good or better for less money.