But in order for your statement to be of value as a warning I think it would be helpful to state WHY DIY approaches do not compare.
Well forgive me, but I thought that was self explanatory...
Anyway, I'll play along so here are some of the reasons DIY GPS approaches, and any other DIY approaches, are not a good idea:
1 You end up killing yourself and other people
2 They provide no terrain clearance (leads to nr 1)
3 Even if you clear terrain you have no idea if you will clear other obstacles such as TV and radio masts, power lines etc (leads to nr 1)
4 It's not legal (due to nr 1)
CP