A little bit of my two pence is that most of my tank has been on a budget. The 4' tank was £20 so on so forth.
Ultimately though, its the simple things with these cheaper versions that need checked out:
does it seal shut ok?
Do the pipes fit ok?
Is the throughput adequate ( I never expect claimed figures)
If its fit for purpose, why not? Its the entire purpose to forums such as this as well: for people who do take the chance to share their fortune or failure to help others.