Let's not crucify No Frills so fast, as this is the lowest price I have seen for the Tomtom Rider 550. It comes with Motorcycle Mount and RAM Mounting kit (RAM mounting kit is not cheap).
Overview
Meet the TomTom Rider 550 - the motorcycle GPS navigation that lets you ride challenge levels, with the best TomTom services. This waterproof sat nav stays connected for calls, messages, and music and is compatible with Siri and Google Now. You also don't have to worry about updating your Rider 550. Simply update via Wi-Fi and you'll have the latest maps on hand.
Australia, New Zealand and South East Asia (SEA) Mapping
SEA inlcudes Bangkok, Hong Kong, Indonesia, Macao, Malaysia, Philippines, Singapore and Thailand
Downloadable via WiFi World Mapping (see Tech Specs for Coverage)
TomTom Traffic and Services
Ride challenge level - Plan windy and hilly roads
Discover the world's best curated riding routes, exclusively
Updates via Wi-Fi®
Discover, personalise and enjoy stunning riding routes with MyDrive
Compatible with Siri and Google Now™
Smartphone messages read aloud
Hands-free calling
Double the processing speed and five times faster start-up
Ok let’s start with the more obvious:
1. The touch screen is unusable if the smart phone is encased.
2. Say you have the more expensive water resistant smart phone, the app and the phone are not purposely designed to be glove-friendly and sunlight readable.
Anyway it’s up to the individual’s use cases. It’s the same reasonings for dedicated devices vs general purpose ones - the former designed to be good at specific tasks, like:
1. Playing games on Nintendo switch vs smart phones
2. Taking photos with dedicated cameras vs smart phones
3. Reading books on tablets vs smart phones
4. Having 4x4s vs SUVs
…