You say “places” and then say “into the field” along with “collect some data … via wifi” and “might do a bit of coding”.
So having supported field staff for a couple decades in various roles couple questions come to mind.
First, will you have access to a decent flat surface (like a desktop/table, etc) to work on? Yes, you see people working with it on their lap at the airport, but really, that’s just because they’re desperate to get it done. You don’t want to work that way
Second, is the “field” basically clean? i.e. Indoor office/store type environment or is it “field” like oil field rig, truck stop, construction site, etc.
Third, are you dependent on interacting with local staff while collecting data and will busting out a laptop be intrusive on that interaction?
Fourth, if this is truly a uni-purpose device, can a simplified tablet or phone be purposed to talk to the data collection device? i.e. could you just use a $59 Amazon BLU android phone with an app to collect the data?
The answers determine if you really what just a $200 disposable laptop, low-end tablet or tabletesque PC like the Surface or Ipad with keyboard.