So, the debate. Little blurb (more thinking out loud than anything else, but if anyone has an opine to share, please do).
Str6, AP-1 (range 18).
Str-8, AP-2 (range 18).
Both have their uses, and with the speed of Reavers armour facing is only a small issue.
The lance has a distinct edge vs AV-12 and below (with a 2d6 curve result of 7, a 13 is statistically probable) and a slight edge vs AV-13 (due to the AP-1 granting a +1 on the damage chart).
With a base strength of 6, though, it begins to lose out (due to the same curve result of 7 imposing a statistical consistency of 13, resulting in a no-pen result).
The blaster has a true range advantage of 9" (no need for half-range maximum efficiency) and a Str edge of +2.
This has the advantage of;
Instant Death vs multi wound T-4 (Nob Bikerz come to mind), greater wound consistency vs T-5+ units, and fewer opportunities for opposing bubble-wrap protection.
The problem is multi-faceted.
Quantity; every additional weapon beyond the first is a minimal unit increase of 75-77pts, and a maximum of 3 weapons..coupled with a unit that can be broken with little firepower commitment. With that in mind, I see a maximum yield (for points efficiency) of 2 weapons.
Investment; these units will die after performing their duty. With frailty of T and Sv, and a max leadership of 9, you can kill/break them fairly easily prior to a pain token being acquired. As the loadout I have is for vehicle popping, odds are you will have to set up a character start or retain the vulnerabilities.
Duality; in a Vehicle killing role, or with a lack of expensive upgrades, a single splinter-rifle on non-lance/blaster equipped bike does not encourage a dual-purpose role for these bikers.