Relocating chickens; Garden or Allotment

We've had chickens in our garden for a few years now but I'm thinking of moving our chickens... Can I canvas opinion?

On work days when we are out they are in a walk in run (3m x 2x) on our patio filled with hardwood chips.  They hate staying in and get quite shouty about being kept in.   When we are home they free range round the garden. 
Pros
* Run is easy to clean
* Don't have to plodge across grass / mud in winter
* Totally fox proof run
* They love free ranging
Cons
* poo all over garden / loads of flies
* Squawking in morning annoys neighbours
* Hardwood chips work out expensive as need changing after 3-4 months
* The new girls are eating all my nice plants 

My reason for moving them is basically so we can have a garden back - the kids used to love doing cartwheels and walking barefooted in the summer, and also its REALLY irritating being woken up at 7am by squawking 

My options are:
1. Move them to our allotment (5 mins away from house)
2. Move them to bottom of garden and fence a section off to allow semi free ranging when we're at home

The allotment could be a good move as they could help cultivate the massively overgrown bits but we work full time so we'd have to visit morning and night and keep they in the walk in run.  I would extend the run though to give them more room.  Its pretty fox proof - anti dig skirt etc but not as much as on concrete.

End of garden would still mean flies and a slightly less fox proof run is it would be on soft ground, but very convenient. 

What do you think?

I had my originals at the allotment, 15 min walk. Summer nice, rain not nice and winter a nightmare esp as water freezes.
I have mine on a concrete base at home (moved house), they free range,I poo pick,but in summer, they can be locked in with a paddling pool dustbath, so children free range in the garden. They do moan, but get ignored.
How many do you have?
I don't have anything on the concrete, so house and pool gets taken out and area hosed, but will brush area weekly.

Also, I found Stalosan F helps with flies/smell