Funny that ThumpTheShoes mentioned Chuck Jones, because when I was contemplating my own reply, I realized that I was having a tough time coming up with an answer, and the first similar comparison I could come up with involved Warner Brothers Cartoons. If you're a fan of the of Warner Brothers Cartoons and you own the stuff from their best and most well-known era [the '40s and '50's], what should you seek out next? The decade of the 1930's, when the cartoons are in their formative stages [but you can see recognizable signs of the classic stuff that was yet to come], or the 1960's when things were definitely on the decline and eventually became unwatchable? To me the exact same comparisons can be made with Our Gang. If you buy the silents, you're gonna get a bunch of films that you will find totally unrecognizable with what you normally associate with Our Gang, but you'll also see some excellently crafted films in their own right. If you go for the later MGM stuff, you'll be fooled early on; the first handful of films seem no different than the Hal Roach shorts, but things quickly go downhill, and by the time you reach the end of the series in '44, you'll ask the same question that you'd ask if you watch the earliest films: "Is this REALLY Our Gang???"
To me it's a tossup: Both options have their good and bad points. You're familiar with the "Talking Hal Roach '29-'38" era, so......... if you want to see a young Farina and Joe Cobb, buy the silents; if you want to see an older Spanky, Alfalfa, Darla and Buckwheat, buy the MGM films.