It was an ideal last-minute Christmas-gift option, but is the new ultrafast Sega Dreamcast video-game console really worth $199, twice what the older-generation Sony PlayStation and Nintendo 64 platforms sell for? We impaneled four veteran gamers to test-drive the Sega, and their verdict -- with one caveat -- was overwhelming: Don't bother waiting for next fall's PlayStation II; the future is now. George, 6, noted that the enhanced graphics were "awesome" and chose Sonic Adventure (Sega, $49.95) as his favorite new game. Sam, 9, conceded the Dreamcast's superior speed and graphics but cautioned that there are still many more games available for the older PlayStation. Eleanor, 10, a seasoned angler, was immediately hooked on Sega Bass Fishing (Sega, $39.95; optional fishing-reel controller, $34.95). The digital fish looked real but "were easier to catch," she said. And M., 44, who wasted his youth playing Space Invaders at an arcade in Times Square, obliterated several recent evenings with Speed Devils (Ubi Soft, $49.99), a gorgeously rendered street-racing game. "The Sega is just this small little humming box," he says, "but it's taking over my life. It's scary."