At first glance they do seem impressive.
However, any host offering "unlimited" MySQL databases is either stupid or has so many PHP/MySQL features disabled that the database[s] would not be usable or useful for most purposes.
Have you read their AUP [Acceptable Use Policy] and TOS [Terms Of Service] ?
About the first thing listed on both pages is this:
IMPORTANT NOTICE: *All Payments To Hydra-Host.net Are Non-Refundable*
Not too inspirational really.
Having read some of the AUP and TOS I, personally, have my doubts. Without going into too much detail I can see a few points listed in those two documents that I wouldn't be happy about.
For the record, I've had very good service over the last few years from Easily click here , 2020 Media click here and 1&1 click here
If you are working to a budget, Easily offer very good value with their Virtual hosted and Enhanced Virtual [for MySQL] hosted accounts.
The hosts I currently use in general all charge around the same as 2020 and 1&1 and when it comes to good hosting you can't argue with that amount.
I wouldn't mind seeing a phpinfo printout from one of the domains offered by Hydra-Host. I suspect you'll find that most of the useful features are not available.
I repeat, any host that offers "unlimited" MySQL databases is either stupid or has effectively crippled them for use. Can you imagine how much data I could fling around with unlimited databases at my beck and call ?