I have not experienced any payment delays with Academic Research, even under the new website interface. However, I have noticed that they have had an increased number of reasons to penalize the writers regardless of whether the problem was created by the client or not. The company does not delay my salary but, they do try to find ways to penalize my work within a few days of the payment schedule through a QAD required check of my submitted work. I believe that is their way of, not delaying the payment, but rather, withholding payment from the writers who have been with the company for a number of years.

I am guessing that the payment delay is something they implement for the new writers whose payment is "withheld" for 2 weeks just in case of refunds. There were times, when I was new with the company, that they did delay my salary from a few days to a whole month. I found that the practice reduced as I climbed the writers ranks though.
These days, I get paid on time, although with QAD required checks on my paper and some "fines" in place for reasons that would make one laugh. The client isn't the one complaining about the paper, it is QAD. So QAD pre-deducts the "penalty", in case the student files a complaint. If the student doesn't file a complaint, I still don't get the deduction back. I know it sounds weird. It's a true story though.
The low CPP rates are for the newbies at the company. These rates increase over time based upon the number of orders taken, quality of papers delivered based on client surveys, orders completed, and a host of other considerations. The company tracks the writers progress through an automated system and, upon reaching all of the required metrics, the writer is automatically promoted by the system. Once promoted, the writer should see an immediate increase in his CPP in the Available orders list. The CPP increases some more for "requested" writers and those who are dealing with repeat clients. A bonus is sometimes given by the company depending upon the reliable and high quality performance of the writer. I did notice that the CPP goes down during the slow months. That is understandable since there are not enough orders to go around but still the same number of writers available. The company has to make money somehow. The good news is, the fines and other deduction considerations seem to also slow down during the slow months for most writers. So yes, the company may pay a low CPP during certain months.
However, if you are relying only on one company for your income in this industry, you will definitely not be able to make the kind of money that one hopes to make as a work from home person. The key to a great income as a freelance writer who is attached to academic writing companies lies in the way you work for the company and how many companies you are attached to. If you do your own direct to client work on the side, then you should be making a pretty decent income overall.