Is there some simple PfR documentation out there?

Question

We are not a large organization by any means:  we have an MPLS network with the HQ and 8 branch offices.  We have a backup MPLS via another supplier.
In the past we had a 6513 at the core of our network and we used a combination of EIGRP with the variance command plus PBR to accomplish the following:    we prefered one provider for certain mission critical traffic, unless that provider was down then all traffic went over the other link.  As long as both links were up, non-mission critical traffc was shipped proportionately over the backup link and the remaining bandwidth of the prefered link.  Ugly to look at, but simple to implement and worked like a charm.
Now, we bought expensive Nexus equipment to replace the 6513 and, well, EIGRP variance command is no longer part of the set. 
I'm left with PfR on the two routers which is infinately more complex than what we need.
Every document  I read about configuring OER/PfR is more essoteric than the one before it.  It's not that there isn't good stuff out there, but getting to the heart of the matter "how do I configure a simple set up" is not to be had.  The info I need to get to is burried under features, design, and marketing hype.
Is there anything out there that shows a very simple set up?  I should have thought a simple access-list type definition for my prefered networks pointing them to provider A plus some way to ration out the remaining packets would not take so long to ferret out but here I am weeks later still reading and not making much progress.
To date I have GNS3 set up and PfR is "enabled and active" on the simulated links.  I just need to translate my once-upon-a-time working ACL/PBR configuration into the PfR syntax.  It's harder than it sounds.
Thanks for any links or examples.

Answer 1

Both these post links contain very helpful info and I've seen some other posts besides that do help but, still running into problem with this. Steve you touched on this in a conversation with our SE and myself on a conference call.
Here's the situation. I need...am MANDATED in fact, to prefer one provider for certain types of traffic, then load balance based on available bandwidth the remaining traffic.
Item one is easy: preferred link groups. But everything I read says that function  is mutually exclusive with load balancing based on bandwidth. So what am I to do? Tell my employer the million dollar investment in Nexus was a mistake?
I hate to sound so frustrated but this PfR solution, while useful to large shops and ISP's, is convoluted to say the least, and overkill for a shop that has a fairly static amount of traffic over an two MPLS networks that simply aren't impacted by many (if any) external factors. Life was fine with EIGRP, variance, and a small number of PBR statements. While that wasn't exactly 'load balanced' perfectly, it was close enough to satisfy the requirements.  It worked well for 5 years and because of how EIGRP worked, failure of any link was undetected by end users.  Simple, clean, effective.
And here's an unrelated question that has plagued me throughout my studies of PfR:  if I have a link that is suffering performance degredation do I really need both passive and active probes adding traffic to that link trying to determine if/when it's time to fall back to it?  Sounds kind of like when I'm trying to fix a problem and my boss is constantly over my shoulder saying, "is it fixed yet, is it fixed yet?"!  How exactly is this helping?
I really need variance back.  without it, I'm not seeing anyway to meet my mandate.