@den-the-coach is right here, and I have posted something similar.
An elite RB or even a top 5 RB can effect the
scoreboard more than Donald can. And that's the difference. Donald is the best defensive player in the NFL in my opinion and I don't think there is even a debate about that unless it comes from a biased Texans fan. There is a reason he easily won DPOY.
However this era is all about offense and a player like Gurley makes more of an overall impact on the
scoreboard. Football in the NFL is not a sport, it's a business and a competition otherwise it would be free and they wouldn't keep score.
The only DT's in the last 30 years that went to the HOF are Cortez Kennedy, John Randle, Warren Sapp and Randy White.
One of those played in the "passing era" that being Sapp, the rest played well before the rules became slanted towards the offense.
If Gurley were one dimensional, or limited or just really good this would be a much different debate and would be one sided. But he is as versatile as any back in the league right now and is growing into a Faulk type of role. I'm not saying he has Faulk's "football IQ" I'm saying he is playing that kind of role. He's a threat in the running and passing game and is a player that can break off big gains or take it to the end zone anytime he touches the ball.
Last year he accounted for about 140 yards per game. Plus when defenses key on him and focus on slowing him down the Rams punish them through the air.
If the Rams are going to be in the mix for the SB for the next 4-6 years they need Goff and Gurley in the backfield.
There are three games that the Rams won last year where Gurley was the difference. With a "very good" RB those may have been losses. The Cowboys game, the Titans game, and the 49ers game early in the year were all wins because of his performance/production.
That's my opinion anyway.