Same quandary recently.
What I considered: Bryton Rider 10 and 15; Lezyne Mini and Macro Easy GPS. But none of the computers for under $100 had every feature I wanted: GPS and GNSS, compatibility with my older ANT+ only sensors (Wahoo wired speed/cadence sensors from 2012, which I really like) and newer Bluetooth/ANT+ sensors (Wahoo Tickr, XOSS induction type convertible speed/cadence sensors).
What I actually got:
XOSS G+. It ticked all the boxes.
- GPS/GNSS
- Bluetooth/ANT+
- Built in thermometer and barometric altimeter
- Weather resistant (it's survived rainy rides so far)
- Front mounted buttons
I had heard of the XOSS Sprint kickstarter project, but not the G+. The cheaper G+ showed up in an Amazon search so I gave it a try, figuring I could return it if it didn't work out.
The XOSS G+ was a PITA to set up but works great. After fussing and cussing for a day to figure out the device and app, swearing I wuz gonna send it back, suddenly it all clicked and worked very well on a couple of test rides.
Amazon must have been reading my mind because I got a notification of a flash sale at half price. Sucker than I am, I bought another for $25. It's waiting for me to finish a bike build (nearly 30-year old Trek 5900 needs a headset overhaul, and I'm lollygagging on my Diamondback Podium frame build). But it'll get used as well.
The XOSS G+ is an interesting blend of a no-frills bike computer like a CatEye -- speed, odometer, etc. -- with GPS/GNSS and compatibility with my ANT+ and Bluetooth sensors.
No navigation aids at all. It only records GPS data for later use when transferred to our phones, Strava, etc. That's fine because I can use my phone for navigation if needed. And if I don't need the phone to record my rides, the battery will last longer. If I ever need a computer with navigation I'll pony up the cash for a Garmin, Wahoo, or higher end Bryton or Lezyne.
Pairing sensors was a snap, quicker than getting my phones ready with Wahoo Fitness (or Strava, when it still supported some sensors). Wahoo Fitness can still be finicky about pairing senors -- some days I need to repeat the whole "Please recognize and identify and memorize my dang sensors" routine with Wahoo Fitness. But with the XOSS G+ it was one and done. It seems to default to ANT+ when available, which minimizes drama over other devices trying to share the same Bluetooth device.
The XOSS app needs work but the developer is on Facebook and responds to user input. The app has already been improved since I got the G+ a couple of weeks ago. The main problem some users appear to have is European and American customers buying a XOSS intended for the Chinese market, apparently trying to save a few bucks rather than buying the European and US market devices. So they get devices in Chinese language only, or maps of China only.
Upload to Strava works fine. Haven't tried other sites/apps. The XOSS G+ and phone want to be very close together to sync and transfer data as quickly as possible. Even 10 feet across the living room was too far. So after a ride I set the G+ and phone together and let 'em sync while I get a snack and drink. Then the phone syncs the transferred data to Strava. So far, so good, easy and reliable.
Presumably the GNSS capability may add a little more accuracy to GPS in difficult situations. One gripe I and friends have had about Strava is losing all ride data if there's a glitch. Or lost sync will cause a straight line between where sync was lost and regained. So far the G+ seems to track at least as reliably as my iPhone and Android. I'm running both the G+ and phone for now, waiting to see if there's a glitch that messes up the phone log but not the XOSS G+.
BTW, it might get the advertised 25 hour runtime between charges if the backlight is disabled. But with auto-backlight and my usual nighttime rides, it'll get about three 2-hour rides before two of the three battery bars are on. I haven't run it to exhaustion yet but I'd bet it'll last maybe 10 hours with the backlight. Still not bad. I'm in the habit of recharging everything after every ride anyway -- lights, phone, computer, etc.