this is Jakub, co-founder here.
From the technical/hardware perspective both "fat" rock beacons and stickers are almost the same.
They have ARM Cortex M0 processor, flash memory, temperature and motion sensor. They have similar BLE chips even thought slightly different size.
Both products are waterproofed and have built-in adhesive layer.
The main difference is the battery:
- large beacons are optimized to last 3+ years depending on the power management settings
- small stickers are designed to last aprox. 1 year
There is also a difference in the software firmware they operate:
- large beacons are designed mostly for proximity and location; they are supported by Indoor Location SDK and they broadcast generic iBeacon packets you can use with Estimote SDK or Core Location
- small stickers broadcast something we call Nearable packets; these packets contain not only the identifier but also nearable type (dog, chair, car, bike, etc), it's motion state, motion duration, temperature and other data. Thanks to Estimote SDK for Nearables it's easy to build context-aware apps that respond not only to proximity but also gestures, e.g. you trying the red shoes with sticker, etc.
What apps do you plan to build? We can advise which beacons are best.