I always get a basic model- 5 functions.
Just want to know how fast i'm going,
how far i've been and what time of day
it is. Plus a total distance odometer.

Have used several Sigma 500 series units,
the last one was 504 or 505, put it
on my wife's bike. The more recent
models are much more difficult to adjust
wheel size and adjust time, etc than
previous models. Too difficult to
fiddle with.
Earlier this week Installed a Cateye velo 5
to replace a Sigma unit that i broke. it was
easier to adjust than the Sigma, but I could
not set the odometer to an already traveled
distance (as one can with the Sigma). Not
sure if I like it yet, or not. The Cateye speed
digit appears larger than the Sigma unit,
not sure they are any easier to read. Clock
and odometer digits are smaller on the Cateye.
Both units were less than $20.