I got Weaver "Grand Slam" steel 2-piece bases on my bolt action rifles, because they're stronger and Leupold 1-piece bases on my lever action rifles. Also have 2-piece aluminum Weaver bases on other rifles. Nothing wrong with either type, and I don't notice any advantage, except I know that the 1-piece bases will not "torque" the scope tube if the receiver isn't drilled in a straight alignment, but if drilled correctly, it doesn't matter, and you'll know immediately if drilled incorrectly. Biggest problem is not all rifles will allow the usage of a 1-piece base. I use Weaver "Quad Lock rings because I found them to have better holding capabilities, giving no scope dents, with the 2 straps on each ring to be better than one large strap, that generally requires lapping. I've heard that Talley and Warne makes very good rings and bases, and that Burris "Signature Zee" rings with the inserts, are superb rings also, if you don't want any scope marks, and they have adjustability if scope is out of extreme alignment, but I don't have any of these rings or bases to access their quality with their higher costs.
Del