Boomer Esiason and Joe Montana.

They are the National Football League's coverboys, prototypes of the cerebral and mobile quarterback the pro game demands. With their drop-dead looks and back-to-back conference passing titles, they are also Madison Avenue dreams.But they're as different as, well, Diet Coke and Diet Pepsi.

"He does a Diet Pepsi commercial that's a straight sell," said Esiason of Montana. "I do one (Diet Coke) where I have to act."

The NutraSweet Bowl comes to Cincinnati's Riverfront Stadium Sunday when Esiason's Bengals test Montana's two-time defending Super Bowl champion 49ers. It's a tangy matchup between the gregarious Esiason and reclusive Montana, pitting distinctive yet effective styles in similar offensive systems, even though Esiason admits he's not having what he calls "a Boomer-type year."

But at 29, the emotional, fiery Esiason - five years younger than Montana - also says he's no longer hung up about being like Montana, the unflappable technician. Or, for that matter, anyone else headed to the Hall of Fame and all points immortal.

"It'd be foolish to think about that stuff at this stage in my career," Esiason said. "I got over all that in '87. I can't worry about my status in the league and I don't. I know what I can do and so do my teammates and that's the important thing."

The important thing, as far as the Bengals are concerned, is that Esiason has used his rambunctious, athletic style to find a way to win. The Bengals are in first place despite Esiason's quarterback rating of 76.6, less than the 87.3 career mark he brought into the season that's third best of all time behind Montana's 94.0 and Dan Marino's 89.3.

"Two of the best who ever played will be on the field Sunday," said Bengals coach Sam Wyche of their mental prowess.

Wyche coached both as rookies. When he was a San Francisco assistant coach, Wyche helped develop the 6-2, 195-pound Montana in coach Bill Walsh's finesse passing game built on timing. As the Bengals' head coach, Wyche allowed the 6-5, 220-pound Esiason the freedom to roll out and throw deep in Wyche's "attack" offense.

At the moment, neither quarterback leads his conference in the passing ratings. Montana has posted an All-Pro 92.1, but his 14 interceptions are already a career high. Esiason's 17 interceptions are just two shy of a career high and he's not happy with his play earlier in the year.

Both have had to deal with changing personnel. Montana, forced to work with a running game rendered less effective by injuries to Roger Craig, has thrown 57 more passes than his previous high after Week 12. Esiason, who spent a month on the road without wide receiver Eddie Brown and Tim McGee in the lineup together, has thrown less than 25 passes in a game five times.

"I get mad at Joe because he makes our position look so easy," Esiason said. "If you look at his last three years, he's been incredible with his consistency. He seems to be in more control of himself than I am of myself, but we're both in control of our offenses."

Yet Esiason probably has more to do than Montana. Bengals wide receiver Mike Barber, who played with the Niners last season, says Montana pretty much stays with the coaches' call at the line of scrimmage.