In a simple answer - YES. That and the Roland Warranty.Is the only difference the speed?
I don't find the SP to be all that bad really. Using Wasatch SoftRIP, I yield 64 SFPH for 99% of my prints, which is exactly 2X what Roland says it will produce (720x720x8-pass). Yes, a finely tuned machine with the right RIP can in fact do that. I also made a banner profile that is something like 540x360x4-pass and it yields right around 165 SFPH. Granted, these aren't neck-breaking speeds by any stretch, but very palatable.
I see that you use Wasatch. What do you think of it? I have been contemplating getting this to use with my VP, but have heard mixed feelings on it. Would you recommend it over VersaWorks?