just assemble a semi-good team and STFs will be the most enjoyable thing you've ever done!
i don't get it why ppl keep crying about STFs, if you find them too hard, don't play them, you don't NEED the borg set.
but PLEASE don't ruin them for the rest of us
You do NEED the Subtranswarp engine if you routinely collect data samples. Having someone blaze past you at Warp 14 time and time again in the clusters is no fun.
Endgame in STO is currently less Raid/Instance Oriented.
Endgame consists of a myriad of activities to get "emblems'" the current endgame currency.
You can do:
Any of the 4 STFs (5-person dungeons)
most of the half-dozen or so Fleet actions (10-20 person instances)
2 Scenarios (ground assault and space capture and hold)
2 Arena queues (with 3 maps each, space and ground)
2 Open PvPvE Warzones
Featured Episodes and their Dailies can award Emblems too
The big problem with this is that all but those STFs are things you've been doing since the beginning of the game. There's no "top heavy" content, meaning most of the content isn't unlocked at endgame--it's been unlocked entire ranks earlier.