There is good and bad. I wanted to buy a brake vacuum pump for our Hilux diesel alternator. Their price was less so I ordered it along with several other parts. They did preliminary parts inquiry from their supplier and said everything can be supplied. Then after 4-5 days later I made the payment. Within days they said the vacuum pump is no longer available at that price so they asked me to either put more money to get it at the new price or do a refund. Issue with the refund was if that pump is not included, then I am not making a good deal due to several other parts are expensive with them and I have to buy it from partsouq.com (which is THE BEST store so far for me: absolutely no complaints) and pay again for shipping. I asked them to do a full refund, they said OK. Then they sourced other parts and asked me to confirm before shipping those. I then insisted to make a full refund. They said OK and on the following day, they are ready to ship what ever the parts they had. I then filed a complain with paypal and got the full refund in 2 days.
Would I buy from them, yes, but I will be skeptical when they have certain parts at excessively discounted!
PartsOUQ has NEVEr given any headache as far as I know to anyone.