PK I only put those up as examples of how even the simple ones are inconsisitent - Im not recommending them...the one I prefer is too complex....but I think it's worth spending some effort worknig out systems over 2nt (because once one partner opens 2nt many hands will be in the slam zone...and so often 6nt is the inferior slam and people often dont have the tools to find the right 6 suit contract)

 

As to rusty's question...If my partner bids 3M and I hold 3 I always choose 4M instead of 3nt....that is one of the few reasons I like puppet.