Edwards on the real Francis Turretin and Peter van Mastricht in comparison:
"Turretine is on Polemical divinity; on the 5 Points, & all other Controversial Points; & is much larger in these than Mastrict; & is better for one that desires only to be thoroughly versed in Controversies. But take Mastrict for divinity in general, doctrine Practice & Controversie; or as an universal system of divinity; & it is much better than Turretine, or any other Book in the world, excepting the Bible, in my opinion." (source)
Both, of course, are excellent - and we hope to see an English translation of van Mastricht in the next few years.