What is the difference between ADSL and RADSL?

[Viper Frag]

What is the difference and which one is actually the better of the two, I know they are both asymetric but what does the R in ADSL mean and what are the major differences that distinguish them apart. Thanks.

 

[Mong0]

These descriptions were taken from DSLReports:

RADSL
Rate Adaptive Digital Subscriber Line - A version of ADSL where modems test the line at start up and adapt their operating speed to the fastest the line can handle.

ADSL
The A in ADSL means asymmetric DSL. This recognizes that for home use, since people tend to be more of a consumer of data than a producer, a slower upstream (upload) speed can traded off for a faster downstream (download) speed. In addition, the ADSL standard allows for regular phone service to be squeezed into the low end of the frequency spectrum. ADSL therefore needs a splitter to be placed during installation.