Well as it regards comparison between using GTpay or probably inter switch directly is that as for simplepay4u.com, as a web developer you don't have to wait too long to integrate a payment gateway on your website.Simplepay4u.com has the API and modules for most CMS platforms.Most importantly,with simplepay4u.com you don't have to wait for settlement days or have payment limits of 3k,I personally use simplepay4u.com on www.cotekit.com.so guys check it out.