We will start off with the following assumption: Record 1.5 is the best way to record vocals into Reason 5 since it integrates seamlessly with the program. However, it is unfortunate that the software is a bit on the expensive side and even if one buys it, there's some ambiguity over whether it will work with a pirated version of Reason 5.
Many ways have been suggested to overcome this problem. One of which include creating REX or WAV loops outside Reason and playing them through NNT-19, NN-XT or DrOctoRex. This is UTTERLY counter-intuitive.
Another way is to ReWire Reason 5 with a program such as Reaper - Again, the process of having to switch back and forth between programs, compatibility issues and the steep learning curve often required to operate the other program makes this another (and correct me if i'm wrong) NONSENSE method.
Finally, someone suggested to me that I try out Sony Acid 7.0 and ReWire it to Reason 5. I've used Acid before and I love it for its simplicity - Not to mention the ability to load VST plug-ins. I haven't tried this method out yet, but it seems to me that this might be my best bet.