I have had pretty fair experiences in the past, so this rating is solely for my most recent order. On Sunday January 10th, I placed my order to be shipped FedEx Ground 2-3 business day. After clicking the "Place Order" button, the 'Address and Payment' screen re-appeared with a message stating that changes were made. Everything looked the same to me, so I went ahead & clicked the 'Place Order' button again. After receiving my email confirmation, I noticed that the shipping method changed from FedEx 2-3 Day Ground, to USPS Priority Mail 2-day, with an expected delivery date of Wednesday, January 13th, which would have worked. Hey, it's only 3 days, even if they are a day or two late I'll be okay. It's a weekend project anyway....what's the worst that could happen?. Well, I'll tell you:
January 11, 2016 , 8:58 am Shipping Label Created AZUSA, CA 91702 (still @ RA)
January 12, 2016 Pre-Shipment Info Sent to USPS (still @ RA)
January 13, 2016 , 5:44 pm Accepted at USPS Origin Sort Facility AZUSA, CA (i should have it already!)
January 13, 2016 , 6:59 pm Arrived at USPS Origin Facility CITY OF INDUSTRY, CA (uh huh..)
January 13, 2016 , 10:33 pm Departed USPS Facility CITY OF INDUSTRY, CA (hmmm, i guess it's on its way)
January 14, 2016 , 11:21 pm Arrived at USPS Destination Facility SAN JOSE, CA (it's close!)
January 15, 2016 , 1:10 am Departed USPS Facility SAN JOSE, CA (...okay...)
January 15, 2016 , 11:57 am Arrived at Post Office SAN JOSE, CA (...okay...?)
Updated Delivery Day: Saturday, January 16. (WTF!?!?!)

This is a business address, and the business is closed on Saturdays. So the following Monday, right? Wrong...Monday is a holiday, so it will be Tuesday, the 19th before i see it.

While a can't completely fault RA, it goes to show that first and foremost, USPS sucks, and second that the limitations of the RA order system do not highlight the fact that when they modify your shipping method, you are not informed of that specific fact. So look closely - if you make it back to the 'Address and Payment' screen after clicking 'Place Order', your shipment method might have changed. Hopefully RA rewrites their order program to bring that fact to their customer's attention. Oh, and if you call them, they will tell you that it was you that selected that method, and USPS is not a guaranteed delivery method. Bummer.