Since Legacy of Romulus launched, those borg spheres now move very quickly and are immune to the effects of gravity well 3. In general, they'll fly towards the rear of the gateway so its not hard to position my ship to take them down quickly.
As for player skill... I hate to say this, but yes there is a huge big gap in the skill of a competent player vs a normal player. I have been using a dps parser to track damage per second (dps) in space STFs. I find it is a good proxy of a player's skill level. Some of the weakest players I have seen does only 1-3k dps whereas a typical Elite STF capable player does between 3-5k dps. Personally, my 9 characters each have ships that can dish out between 6-10k dps. The very best players I know have ships that can now dish out 10-20k dps. The most dps I have seen is 25k from a Kumari and 26k from a Jem Hadar Attack Ship.