Hmm. They're slightly different guitars so you'd wanna play them and see which feels best to you. That said, there are a few similarities: both are made in Mexico, both have vintage frets (i.e., small) and trems, they each have a polyester finish, and both are typical Strats as far as controls and such go.
The 70s Strat has a 3-piece body, which is just wrong on a natural finish. The MexiAnn Strat prolly has at least as many pieces, but at least you can't see 'em. I'm not sure which set of pickups are gonna be better. The 70s Strat has a U-shaped neck and a 7.25" radius, while the MexiAnn has a modern C-shape and a 9.5" radius. Those specs are gonna be where your biggest difference comes in.
I think it's bizarre that they have 70s Strats at all. Until recently, when they became "vintage" and therefore desirable, most people turned their noses up at 70s and 80s Strats.
Here's my unsolicited advice: Buy a second-hand American Standard Strat.