Used many times for business and pleasure, never a problem so far
Have been using these guys for years to compare rates and make bookings, and have always ended up with a good car from a reputable company and no problems along the way. That said, I've luckily never had a breakdown or an accident to try and sort out - but I wouldn't expect any issues when dealing with Europcar or Thrifty.
Those who seem to have had problems have been hooked up by HA with less professional hire companies and I guess that the weakness of the system is that you don't know who you'll be dealing with till you confirm your booking whereas most people I'm sure would be happier to pay a few quid more to hire from a proper company.
So all up whilst my own experience has been good, it does sound as if HA need to do a bit more vetting of their partners and provide better customer service as and when problems do arise. For those less inclined to take the risk of booking blind then if you have the time you can use this site to calibrate your price expectations and then double check those rates against a reputable supplier like Hertz's own rates and decide whether you want to take the gamble.
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