Ways to play PSO online on Dreamcast?

The last official Dreamcast PSO servers (JP and EU) were shut down in April 2007.

Can you still play the Dreamcast versions of Phantasy Star Online and Phantasy Star Online ver. 2 online?

I read that http://schtserv.com/ and http://sylverant.net/ are popular private servers. Do they (still) work?

Are there more servers than that? And do these servers differ in supported features? Can you use your old characters? Can you play together with players on other systems than Dreamcast? If you'd play on several private servers, could you use the same characters for that? Are there problems with cheaters? Can PAL and NTSC players play together?