GPS tracking is a function of the GPS chip used, the antenna, and to a lesser extent the software running them. A phone requiring an always-on location fix will obviously have a head-start when the GPS app is run up. Also, the cell-site info and to a lesser extent any WiFi info will assist in narrowing down the location to speed up that first fix. A-GPS it's call, at least on the WiFi side.
I've not done full side-by-side comparisons between my CyberNav (Android tablet) and my Dakota 20 but, seat of the pants, the Dakota wins on first lock in difficult situations. It will simply pick up satellites where the CyberNav won't. I'd say the CyberNav has just as good, if not better (newer anyway) chip, but it just doesn't have the space for a decent patch antenna. The Dakota is built around the antenna; the CyberNav is built around the screen. Thus, the CyberNav is a little more like my old Etrek... sometimes I need to move to a better location to get a fix. But, once it's got that lock, it seems quite tenacious.
I'm talking about deep woods stuff. Out on the road, you're not going to notice the difference and the A-GPS stuff might even give a tablet/phone an advantage.