I haven't had much experience yet with .24 (just a few hours of testing a vanilla instance), but I would think that a large consideration in the MPL effectiveness is also if/what mods are being used. DRE (deadly re-entry), for example, will make returning anything much more difficult, and sometimes not worth the cost or complication. I personally refuse to play without RemoteTech 2, and so I like to find uses for those expensive and time consuming satellite constellations I put up. Having a mobile science lab available would seem, IMO, to be a very good way to make them more effective. But I also prefer the role-playing school of KSPing, rather than min-maxxing the science system.