Palerider, the quick, not very helpful answer is "it depends".
Some things you should consider
1) Can you put the Hive(s) behind a shed or some fencing, hedges? The further away you can put them from the parts of the garden you want to sit out in the better. If their line of sight to the rest of your garden is blocked then even a "grumpy" colony can be less disruptive. Out of sight, out of mind seems to work both ways in my experience.
I keep my bees on my allotment,they're behind a ring of brambles and we happily work the plot maybe 2 meters away from the hives without disruption. One colony went queenless earlier in the season which made them very grumpy, at that point we simply couldn't work the plot for any length of time as the brambles weren't high/dense enough and we were continually chased off the plot.
2) How visible would the hives be to your neighbours? And do any of them have kids? You can take two approaches with neighbours, ask them or hope they don't notice. Some will be fine, others really wont be keen on the idea of bees so close to them and these are the people that'll cause you no end of problems once they realise there are beehives close by.
3) How close is where you're thinking of putting hives to parts of your neighbours' gardens that they like to use?
Opening up a beehive puts a lot of bees in the air and most of them not too happy that their home is being disturbed. If you've got neighbours the other side of the fence sat in deckchairs sipping pims while you're protected in a beesuit then that can cause problems.
You don't need a huge amount of space to site a hive. A standard national Hive is 46cmx46cm (a bit wider at the roof) so if you can make up a square from scraps of wood or garden canes, use that as a guide. Where you're thinking of putting the hives, plonk it down and make sure you can comfortably walk all around it and have space to put the same size down (typically as you inspect a hive you take off the roof and place the boxes etc that you're taking off into the roof beside you) to one side.
Also second the idea that if you do keep them in the garden that it's worth having a backup site that you can move them to in a hurry if things don't go to plan. It's more than possible to happily keep bees in the garden but bees can be tempramental.