This is a fluff/rules crossover.
Consider the chainsword. A weapon that is every bit the melee counterpart of the holy bolter: loud, brutal, obnoxiously over-the top (it's a handheld chainsaw!), messy and bloody.
When a Space Marine (of either allegiance) is drawn in an art piece, he's frequently pictured with a chainsword, because - face it - it's the least boring of all choices. Sometimes an axe is just an axe, and a sword just a sword - even if they have the "crackling energy field" about them, and while powerfists are pleasantly out-of-proportion, they just don't have the chainsword's, well, gumption. After all, if you wanted to brutally kill something, would you rather saw it in half showering everything in gore and bone fragments, or punch and crush it to death?
Yet on the tabletop, the chainsword is quite humble, relegated to the role of the utterly bland "CCW" that does nothing other than grant an extra attack. The only time it makes a good showing is in assault-heavy armies, and even then the final word is spoken by "the hidden powerfist". I stubbornly stick chainswords on sarges in my Las/Plas squads even though a bolter would probably make more sense - but it's just not "sergeantly", IMO, not to brandish the toothy implement of death and destruction.
Do you think a chainsword should receive a "slice of glory" someday to make it a slightly more unique and desirable weapon? Perhaps make it a choppa's equivalent (treat everything better than 4+ as 4+) or somesuch?