I've chosen the SECS as you can set alarms and it records the peaks
its also a price valued item and its brand new.

Pectel are only available as second hand and the data logger is useful only of you can modify your fueling and ignition maps in my mind..

The collins is a copy of the basic pectel monitor so no logging
To me the only miss of the SECS would be Air/fuel ratio display as well as EGT
but these can be fitted separatly with a zeitronix for instance (for those who wants data logging) or by two additional gauges