I can give you a summary on nearly 175 feedback from individuals over the past two years on Chaleur Terre:
http://www.chaleurterre.com/forum/viewforum.php?f=18
This is not an exact reflection of the situation in France because there is not yet feedback from Sofath experience for example, but it is better than that: it is the reflection of enlightened individuals who have inquired before their installations
or who inquire after 
but who make the effort to understand their facilities.
This is also why we don't have Sofath presentations for example, but to find you like on all forum a lot of descriptions of individual actually having problem with Sofath it should not be denied
even if it is no longer a reflection of the market today.
I confirm that a very large part of the installers take advantage of the market craze and the tax credit. So watch out for the margoulins
make several quotes and submit them to earth heat 
That said, we must recognize the major interest of this technology when it is used in the rules of art which is not actually always the case. the use of aerothermal energy in cold regions of eastern France for example, over-dimensioning problems or, more rarely, under-dimensioning., questionable installations with equipment which is not always up to par in some case but more rarely.
So what should we do?
Prepare your project well by not rushing on an Aerothermal solution without studying the other solutions in order of the most efficient yield, so you have to study the 4 main solutions without preconceptions:
- On the water table, checking the water level in the well which must not be more than 15m deep ...
- horizontal sensor if your terrain allows it, the sensor should ideally be between 80 to 120 cm deep, but not 60 cm as we see too often.
- vertical probe this solution is studied when there is no water table, no sufficient ground and that for questions of too low reference temperature below -7 ° C the aerothermal solution is in this case not desirable for example in Alsace -15 ° C reference, but the solution is more expensive and the amortization of the sensor will be done over a long period of 20 years the cap must be amortized over 7 years for example.
Then if you have an oceanic climate see Mediterranean you can and it is even desirable to take this solution. 25% of cases normally.
There is therefore indeed a problem of choice because the solution on air represents more than 50% of the choices whereas it should only represent 25%. This is due to a very strong inappropriate marketing and commercial pressure, but also to solutions in succession of boiler for the renovation or this is after all a less aberrant use in cold region.
It is a project which will take you seriously 6 months to see more if you associate it with solar for example
Always check the skills of the craftspeople who are overwhelmingly incompetent to say the least
They will have you particularly validated the calculation of the loss of your home and check the dimensioning which will be proposed to you. A cap is not a boiler, it is very necessary to calculate are dimensioning it is essential 9 times out of 10 the installers do it with a big ladle to say the least
you will need an installation diagram and check it: buffer tank or not, well pump well dimension EDF subscription for power ect ....
there are a lot of points to check
Calculate your return on depreciation but also your annual operating costs.
It's good to take a cap on air cheaper than a tablecloth solution but if your electric bill plus subscription comes back to you 50% more expensive per year and that over 20 years you will have bad surprises.
Likewise if you take a solution on a tablecloth and your installer puts a big well pump on you which will consume 1kw / h for 2m3 / h you will very quickly end up with a cop of less than 3
So Pac solutions are excellent economic and ecological solutions but they are reserved for individuals who want to take the trouble and we must not fall into the clutches of incompetents who are effective we must recognize it legion
So good luck with your research.
As for me, I will continue to use my cap on the tablecloth with a cop greater than 5 when the solar does not do the work alone
and as I have a micro cogeneration project ... I will seriously study this scenario (even with air air in addition it remains interesting) ...
