Swiss Micros makes HP 'act-alikes' - programmable

[edryer]

I own a DM-15L (and DM-16L) as well as an HP-35s. I use the HP35s for Algebra and Trigonometry and math up to about College level, and the 15L for College Level math (first year Complex Numbers/Vectors/Matrices) - by the way I am an older student (I received my bachelors degree back in 1997).

I would really like to just use the DM-15L for everything (the ability to load/save state and develop programs offline is fantastic esp. with 999 steps!) but am worried about keyboard durability.

Has the keyboard been designed for heavy use? Does anyone here use a Voyager form format Swiss Micros device can comment on daily use long term?

I guess the good thing is I use the DM-16L rarely and can "swap" over the internals in case of failure, and flash the 15L firmware.

Thanks.