G'day Reskal, welcome to GPS Power. This section is fine for your thread, np.
Maybe you've pretty-much sorted it already with this alone:
Add to that, water rating and battery life/versatility:i mean the most important for me is reliable navigation and a good range of maps, much more i don't need.
What i also like at the garmin is, that it can use both satellite-nets, GPS and GLONASS.
- GPSMAP64s has IPX7 against Teasi's IPX5. Splashproof [IPX5] is ok in the rain or dealing with road splash but maybe it'll drown if you drop it in a creek, or end up in in there yourself bike 'n' all [Heaven forbid!]. The Garmin will survive a long dip - IPX7 will protect the 64s for up to 30 mins in 1 metre, so even for a short time at deeper depth it'll survive.
- Teasi has built in battery and 10 -12 hr life, only rechargable via usb connection. Garmin has user replaceable 2 x AA and up to 16 hrs, in a pinch it can use even crap torch batteries to limp along.
To me it's comparing apples and oranges. The price isn't a consideration imo, safety and reliability rule especially if you're heading off the bitumen. If you're only road touring in populated areas and staying in hotels/motels overnight buy the cheaper Teasi. If you're off-road with a mountain bike, camping out in the bush and can't risk any dodgy satellite fixes then it's a no-brainer, buy the 64. [just sayin' ].