I never open limp, but if you're into that sorta thing
suited connectors are deinately better to limp, but you'll still face tougher decisions than if you raise preflop.
For example, you limp 78s and end up in a 5-way pot. The flop is 885...if you run into resistance you don't have the greatest kicker with your trips so, once again, a tough spot. Baby flushes are also tricky.
Raising preflop allows you to narrow down your opponents ranges (with most "normal" villains anyway) which makes postflop decisions easier.
Position is also an issue here. I think overlimping scs is fine if you're not comfy with raising limpers AND can play them correctly postflop, but limping these from EP...ugh...I still don't like it. It's so much easier to just play tight from EP and MP, then open it up when you have position. (read: basic TAG) My preference of style, anyway...
Maybe just drop those speculative hands for a while from early position and see if you notice any change in the amount of "tough spots" you're seeing?
Hope that's helpful. gl