[List Building] Land Speeder or Attack Bike?

I've run up against a giant stand still for painting my Night Hawks bikes.  I had singled out 2 five man squads and the captain, airbrushed everything, done the highlights  and then started to paint the silver trim. 
That's where this story ends.  Having no real tactical reason to bring any bike squads since I've lost every game (3-4) that I tried with them - and badly.  So other projects have started in their stead.  In an effort to motivate myself I want to find a use for them and to that I ask the public:
What is better for a suicide multi-melta?





Similarities:12" and fire
24" turboboost
BS 4
Fast Attack Slot

Attack Bike Pros:
3+ coversave (vs 4+)
Easier to hide behind cover
Can tarpit shooty units
Can survive lascannons (1+ still fails to wound)
10 points cheaper

Land Speeder Pros:
Can escape a close combat if it survives
More resistant to small arms fire
Less resistant to heavy weapons (las cannons instant glance vs 4+ cover)
Better at contesting objectives (though as a suicide unit I don't give this too much weight)
Can get lucky on damage chart and survive shooting
Can deepstrike (though most times I'd want to suicide I don't want to wait).
Skimmer

ResultI'm undecided.  It seems like an attack bike can be hidden (behind a rhino for example) and has a hard 3+ save while it attempts to suicide.   I think it boils down to whether you're running a vehicle or infantry heavy list.  When you have more vehicles I'd rather take speeders since they're more resistant to small arms and heavy weapons will be shooting bigger tanks.  In an all infantry list I'd rather bikes which have an easier time hiding while they make for the enemy since heavy weapons will have no other targets.
Any thoughts on this?  This MAY help me paint my bikes (or at least 2 attack bikes haha).