CLS still allows up to two foods eaten between hits so you can forget about comboing to death unless you max 2-3 times in a row (very unlikely).
Maul can combo to death just by the huge hits (its literally an INFINITE BGS SPEC with upgraded accuracy), wont even matter that they can eat twice. Rapier is an upgraded whip, and IMO not worth it UNLESS you max your str bonus with torso/bgloves/fcape/imbued rings/pvp arm. If you plan to welfare you'd be wasting the rapier as plenty of others will hit comparable numbers to you with better gear +whip.
To compare some numbers:
We will assume 99 strength, 15% pray, super pot, zerk helm, rune def (where applicable), str ammy, climbers, bgloves.
CLS Max Hit: 503
Rapier Max Hit:459
Maul Max Hit: 572
If we add max str bonus (degradeable) +imbued rings.
CLS Max Hit: 549 ~9% increase from normal gear
Rapier Max Hit:505 ~10% increase from normal gear
Maul Max Hit:618 ~8% increase from normal gear
As you can see the numbers show a trend that the more you're willing to risk, the greater the effect of the rapier increases. We can also infer that if we lower the quality in gear, we get a greater decrease in effectiveness in this order (1.Rapier 2. CLS 3. Maul). In welfare gear/badly quested gear, the maul reigns superior while the CLS (in my opinion) is never the first option for PvP.
So in conclusion, if you plan to welfare get a Maul.
If you plan to go bonesaw style, get a Rapier.