Hi SB2,
Just so I don't give wrong information, are you in my project (i.e. your name appears on webpage). If so, yeah continue using PRP, since we are doing k*2^n+1. If you are not in my project and would like to join, email me as per instruction thread so I may give you a line number.
If you are not in my search but test numbers of the form k*2^n-1, then stick with LLR all the time; don't use PRP. As you know LLR has huge speedup for small k so you want to use that. Plus, even if you aren't using small k mode, stick with LLR because "normal" mode isn't buggy. Plus I like what Jean did with LLR, he used the Lucas-Lehmer Riesel algorithm, so all the numbers you test for k*2^n-1 always report back if composite or prime. When it says prime, it is 100% prime, because LLR always does a deterministic primality test, so it is always correct and proves outright primality. Older PRP uses probablisitc probable prime test (I thinnk) which is 99% accurate, and doesn't prove primality, requiring an extra step of using OpenpFgw for Proth.exe to prove primality.
Hope that helps.
regards,
william