I love mine, not that good for recording, but for live use and practice is awesome, about the construction well, i got mine like 5 years ago (got it used), and i use it a lot, i retubed and sound a lot better, never had a problem, is built like a thank. really don´t know why people don´t like it, i had it once face to face to a triple rectifier and it did a decent battle, they sounded really similar together, of course the mesa is better, but it doesnt mean the b52 isn´t good, i think is an awesome amp for the price, don´t forget this amp was designed by bruce egnater. and sorry DestroyTheColossus, but there is no way a marshall mg100dfx sound better than an AT100, maybe that one had bad tubes or something, i also had a Marshall MG100.. or maybe i got lucky and got a good one out of a bunch.