Hello Mohammad,
i've not tried the trial version of Enthuware, but directly bought it. I already used Enthuware for OCA SE5-6 and it's been incredibly useful.
As you said in the beginning, author Mala Gupta writes that it's good to take ten or more mock exams. Enthuware gives you 6. Mala's book (or another one) gives you one, so you are 7.
I was thinking to purchase another set from whizlabs, also if it's more expensive than Enthuware....
whizlabs link
it gives you 4 more exams, so you go to 11. And i think that at that point you should be pretty sure to pass the exam.
(i prefer to spend some more with material study, than to pay two time the exam...).
Else there are also this resources, given by enthuware forum, but i've not yet seen to them.
Enthuware links for free mock exams
Consider that the aforementioned Enthuware link refers to the sun version of this certification.
HTH
Alex