I've been playing Warhammer 40,000 since the last year of 7th Ed and I've had some extreme problems with Space Marines since the swap. While the army was still in 7th Ed, it worked great: 3+ or 4+ saves all around, lots of boots on the ground, could reach out and touch just about anything that i came up against (aside from Belial cheese lists) to the extent that i won about as many games as i lost. With the change to 8th Ed they lost about all of their advantages: AP reduces the armor saves instead of ignoring them on certain thresholds, the detachment and price updates reduce the number of units on the table and BOTH of these utterly kill the my ability to reach out and touch whoever-the-heck. I've tried just about everything with these guys; cram a captain, lieutenant, apothicary, ancient and a few command vets into a vehicle and give them multi-meltas while the rest of the army distracted the enemy (didn't work), built a screen of 6 scouts while 3 sniper squads and the rest of the army fired from behind them (didnt work), built an army with deepstriking terminators with Cyclone rockets and chainfists that killed the big stuff while snipers, thunderfire cannons and librarians took on the little stuff (didnt work either). Just about the only useful thing i learned while trying to make these guys work is that StormTalons are a 174 point unit that kills a maximum of 2 units before it's promptly crushed under the shear mass of fire from everything shooting at it.
I spent a good deal of money on my collection and there's simply too much on my person to even THINK about getting anything else, and i truly want to make this army work, so how are you supposed to field the run-of-the-mill Space Marines?