They are both very good lights. the T8 and the F2.
T8 25 watts, 175 mills, 4000lm > less focus, taller beam. power converter in the heat sink, no module in the cable. light pattern is close to the original halogen bulb......
F2 30 watts, 090 mills, 5000lm > more focus, thinner beam. power converter in the cable. Light pattern same as original halogen bulb.
Both H4 bulbs create a DOT compliant beam pattern, but fail because they use half the power, and produce more light....... they are the same or slightly better than HIDs.....
If you read the DOT specification for the H4 halogen bulb, it is a manufacturing spec that insures that bulbs produced by different manufactures are identical in every way...
A new DOT spec needs to be written and the F2 LED should be the mold around which it should be made. The tolerances should allow that the T8 should be acceptable. I hope we do not have to wait 21 years like we did for the H4 to become the 9003....
EA6BMECH: the bulb you got is the S1 which is a fanless version of the T8 but 22 watts. So you should be ok because the ST gets a lot of air flow behind the bulb, as long as you are moving...... Let us know how it works out for you..