One of the main advantages you can using the new USB Type-C connector is the ability to charge for mobile phones and tablets much more rapidly compared conventional USB chargers.
To demonstrate this, I compared 3 similar sized and class of phones- the Samsung Galaxy S6 Edge (2600 mAh Li-Ion battery), the Apple iPhone 6S (1715 mAh Li-Po battery), and the LG Google Nexus 5X (2700 mAh Li-Po battery).
The Samsung Galaxy S6 Edge uses a USB Micro-B Connector and comes with a Samsung 5 Volts 2 Amps USB Type-A charger
First, when connected to Samsung charger, the Galaxy reported that it would take 1 hour and 37 minutes until fully charged when the battery charge level is at 1%. The actual time is fully charge probably closer to over 2 hours since the charging rate slows down as the battery gets more full.
The Apple iPhone 6S uses Apple's Lightning connector which I connected to Apple's 5 Volts 2 Amps USB Type-A charger.
Unlike Android, the iPhone doesn't have a graphical view of charging and also doesn't estimate how long the battery will charge. I connected the charger at 12:08 pm when the iPhone's battery was completely depleted. Within 3 minutes, the battery charged to 3% and took almost 2 hours to charge to 96%. The last 4% to reach 100% charge took about 33 minutes.
With LG's Google Nexus 5X using USB Type-C, you get bumped up to a 5 Volts 3 Amps USB Type-C Power Charger versus the 5 Volts 2 Amps typically found with USB Type-A chargers.
With the new Android Marshmallow, the home screen conveniently shows how fast you are charging and how many minutes until the charging is full. After plugging in a battery depleted Nexus 5X into its USB Type-C charger at 5:03pm, I was able to almost immediately turn on the Nexus. This is impressive compared to other non-Type-C phones where you typically need to wait for over a minute of charging a fully depleted battery before you can turn on the phone.
Upon turn on, the locked home screen shows Charging rapidly and the Battery screen in the Nexus' Settings reports Charging on AC.
However, once Android Marshmallow is able to calculate how quickly the battery is charging, the locked home screen now shows Charging rapidly (49 mins until full) with the same information reflected in the Battery screen.
After 1 hour and 4 minutes, the Battery screen showed the battery had only charged to 76% and showed 21 minutes until full.
As the battery got more fully charged, the battery charging rate slowed down dramatically as could be seen on the battery charging graph where the slope was leveling off as it got closer to 100%. Still, the rate of charging is significantly faster than that seen with the Galaxy S6 Edge and iPhone 6S.
An alternative to the Power Delivery technology that USB Type-C connectors use is Qualcomm's Quick Charge technology. However, USB Power Delivery over Type-C has the advantage of standardization, data and video support, and broad industry adoption.
Given the rapid charging and all the other cool things you can do with USB Type-C, expect a wave of new products adopting this technology over the coming years.
After testing the products above, I felt guilty for not adding a Microsoft Windows phone with USB Type-C to the mix. The Microsoft Lumia 950 is the first Windows phone with USB Type-C and has a 3000 mAh Li-Ion battery.
Windows doesn't have a way to track battery charge in the same way Android does, but starting from a depleted battery, it took about an hour and a half to complete charge the battery using the Lumia's 5 Volts 3 Amps USB Type-C charger.
With both Android and Microsoft phones showing extremely fast charging time using USB Type-C, expect most mobile phones moving to USB Type-C in the future.