I personally think it's moreso user preference and that there really isn't a right or wrong answer.
Obviously high res is cool, though not necessary, for bigger screens that support 1080p (basically all 15" laptops these days).
Similarly, high frame rate is cool, but also not necessary (most screens only support up to 60 fps if I'm correct).
My advice: Start w/ 720p 60fps if you're starting out just to get a feel for your own preference, then play around w/ 1080p30 if you find yourself not really slo-mo'ing anything past 80%. 4/5 of 30 is 24, so anything slower will appear with an arbitrarily noticeable, lower frame rate.
18-23 frames is pretty indistinguishable to the untrained human eye, so you can always "cheat" a little (if you consider it cheating). I shoot 1080p60 and sometimes will ramp shots down to 25-30% (~15 fps, definitely noticable) b/c its ski filming and there's no rules unless you're a serious business kinda guy