CRP-1 & 5
Hi MikeNE3,
If you do not intend to 'go commercial/professional' then you definitely do not need a CRP-5, while this computer is essential for anybody doing CPL or ATPL.
The CRP-5 differs from the CRP-1 only in that it permits calculations involving Mach numbers etc, which are only of interest to those operating high performance aircraft at high altitude.
Using a CRP-5 for PPL work is a waste of money.
Regards,
Broomstick.