Are all Oil Filters the same?

Like most everything, when buying an oil filter you get what you pay for.
Things that affect quality and performance of an oil filter are:

1. Size and thickness of filtering media
2. Quality of the filter seam. (weak seams allow leakage)
3. Type of filter media. 
4. Anti-drain back valve.
5. Pressure by-pass valve.

Size and thickness of filter media will determine what size and how much contaminates can be held before the filter is restricted enough that oil has to be bypassed and non filtered oil sent through the engine.
The oil filter should incorporate an overpressure relief valve to allow oil to bypass the filter if its flow restriction is excessive, to protect the engine from oil starvation. Filter bypass may occur if the filter is clogged or the oil is thickened by cold weather.

 Poor quality filter media and seams can allow contaminates to eventually get through and back into the engine.

Higher quality materials used in the anti-drain back valve will keep more of the oil from draining out of the filter overnight, allowing oil to reach the engine on startup.
Without a good anti-drainback valve pressurized oil would have to fill the filter before travelling onward to the engine's working parts. This causes premature wear of moving parts due to initial lack of oil.

It is easy to skimp on some or all of these items and produce a "bargain" oil filter. Excessive engine wear may be the end result.