Range is another one. An ICE engine has fuel for 600km (20,000 hexes at cruising speed). A fuel cell has a lesser range of 450km (15,000 hexes) (TechManual pg. 68)
Thats for Battlemechs (well Industrialmechs)
IIRC the Errata for vehicle range states that the fuel tank is 10% of the engines mass, and follows support vehicle rules so 100km for an ICE is 1% of the engines mass, Fuel cell is 1.5%
So a ICE equipped tank has a range of 1,000km and Fuel cell 667km.
Though Industrial mechs it's as you state, 600km for ICE and 450km for fuel cell, an extra fuel tank is 10% of the engine and doubles the range (I.e. it adds an extra 600 or 450km of range).
As for the Topic at hand
IIRC Fuel cells are more expensive than ICE but are cheaper than Fusion, they also weigh less than fusion engine vehicles (which are also lighter than ICE), as such unless you want to use a lot of energy weapons or are worried about refueling, then Fuel cells are better then ICE or fusion engines. On the other hand the Light and XL Fusion engines are lighter than Fuel cells.
In short
ICE: Still good for extremely dirt cheap units, but pore on anything else
Fusion: Good for unlimited range or energy weapons, other wise inferior payload to Fuel cells
Light & XL Fusions: Have better payload than Fuel cells as well as being better for energy boats