A good MIM Precision Bass is an excellent bass. Reasonable minds can (and do) differ over whether and how much a MIA Fender is better than a MIM, and whether that difference is worth the additional money. Certain hardware and electronics are nicer on the MIA models, but those things are all pretty good on MIMs. Is a Classic Series $300 better than a Standard? Is an American Special $400 better? Is an American Standard $700 better? Only you can answer those questions for you. (You can go the other way, too---is a MIM Standard $200 better than a Squier Classic Vibe?) You will find plenty of people on TalkBass who will support answering any of those questions either way.
Here's what I think is the most important thing to understand and remember about Fenders: Every Fender bass is the sum of its parts, and since some very significant parts in that mix are made of wood and thus never exactly the same from bass to bass, every Fender is a little bit (or a lot) different from the others, even if they look exactly the same. Sometimes the parts just come together in a special way to produce a bass that really comes alive in your hands. Now, you can find basses like that at every level of the Fender/Squier line. If you find a MIM Standard that has IT, don't let it get away just because it is theoretically not the best bass in their product line. If you're looking at a specific bass at a store or whatever, and you've played it and you like it, that's way more important than debates over the subtle distinctions between various models. This is especially true with Fenders because they are the most easily upgradeable basses on Earth.
Again, even without upgrading, a Standard Precision is a fine instrument. I doubt that even people who don't like the hardware or pickups or whatever would dispute that. If you really want to know the specific differences between the various Precision models, you can look up the specs on the Fender web site and see exactly which pickups, which bridges, etc., the various models have. That will be only marginally helpful, because they're all Precision Basses and they will all sound and feel pretty similar. To really understand the differences you need to play a bunch of them, preferably next to each other. But if that's not an option, you don't need to fear that if you get a MIM Fender you will be getting an inadequate or insufficient model. They're good, solid basses.