I have to say its almost always user error - except when it isn't 
Some attys are just crap - thats the nature of things unfortunately - ever had a car that was a lemon from day 1? How about a vacuum that sucks so bad it blows? I've had stuff I've bought that really let me down from the get-go - kind of puts you off the whole product from that company - or even the item itself (we've all been there I'm sure). My bete noir is toasters - I can never find one that toasts evenly, or its too small or it doesn't take buns..yeah...toasters...
And then there's the item that just won't work, untiil you find out there was a switch you were supposed to press, or a plug you had plugged in, or you didn't read the instructions cover to cover and missed a vital point (oh thats me lol).
The main problem is not KNOWING if its you or it thats at fault. I think thats likely why you've felt so frustrated (as would we all, I'm sure) but hey..by the end of all this you should be an EXPERT of the functioning of a 510 right?

Some attys are just crap - thats the nature of things unfortunately - ever had a car that was a lemon from day 1? How about a vacuum that sucks so bad it blows? I've had stuff I've bought that really let me down from the get-go - kind of puts you off the whole product from that company - or even the item itself (we've all been there I'm sure). My bete noir is toasters - I can never find one that toasts evenly, or its too small or it doesn't take buns..yeah...toasters...
And then there's the item that just won't work, untiil you find out there was a switch you were supposed to press, or a plug you had plugged in, or you didn't read the instructions cover to cover and missed a vital point (oh thats me lol).
The main problem is not KNOWING if its you or it thats at fault. I think thats likely why you've felt so frustrated (as would we all, I'm sure) but hey..by the end of all this you should be an EXPERT of the functioning of a 510 right?