They are aqueon tanks, excellent quality for what they are.
I persoonqally think they are just aws good as any other small tank. i picked up another 40 today though and had to pick through4 tanks before i found one without air bubbles in the silicone. it was on the same seam in every so its probably where the assembler was reaching to smooth the joint. i didnt see that problem in the other size tanks.
If only I had room...sigh