Sorry Grant, yeah, the posted article is wrong. What makes it funny is that they thought SEGA developed Top Spin 4, however they did not. Top Spin 4 is developed by 2K Czech (previously known as Illusion Softworks), who have nothing to do with any of the previous Dreamcast 2K titles and has no connection to SEGA past or present. Well... as Illusion Softworks they did develop Hidden & Dangerous which is on the Dreamcast. Though that was a PC port and has nothing to do with tennis.
Personally, I'd go for Virtua Tennis 4 because... it's Virtua Tennis! The original developers! Top Spin 4 has received positive reviews, though I know little about that series and as a SEGA fan I'd have to go for Virtua Tennis. You can get mugged playing exhibition mode! That alone makes VT4 the better title.