Electric brake draw backs. Most need electric to release. Meaning if you loose current while in motion? The brake will come on very hard. Seen electric brakes on MPE Yales & Hysters actually throw the operator off the truck while in rabbit speed. When hitting a bump because of a bad battery coupler. Also yes some trucks have release bolts & tow switches. Hysters & Yales have a brake jump out plug on walkies & 3 wheel trucks & Stand up end controlled trucks. Some have juper plugs available to buy. All need at least 12v to release brakes. If batteries go dead in a unit like a walkie on a delivery truck? Jumping the plug will not work. So the driver needs to carry a 12v jumper pack. With a mech. brake you could move the truck. With electric brake. Without power the truck has to be picked up. Hyster & Yale are still having a lot of issues with electric brakes burning up. Electric brakes are easy to service. But I think the mechanical brake is still better operating. They are gaining on it though. On the new 3 wheel AC trucks. They are using a electric brakes for parking & Mechanical wet brakes for service brakes. Also on all trucks 3 wheel and new IC trucks with wet brakes they are using hydraulic tractor oil in master cyls. Seen techs already making mistakes putting in dot3 or 5. Which causes leaks internally in drive units. Due to brake fluid not being compatible with gear oil in drive units. Electric brakes are on or off. Restraint can be adjusted on some. But the old enemy is still there HEAT! Take your pick here? ETS.