MACBWT is correct.
I posted this in another thread but will share here as well just in case.
I have an 07 Edge and was having similar issues. While accelerating up the slightest incline giving little pedal depression the vehicle would shake/shudder/vibrate. It would also do it at cruising speeds 50-60MPH.
I'm a tech so I have the ability to check and go fairly in depth for diag.
Come to find out, the engine was NOT the problem. The guilty part/parts were the TSS and OSS in the trans.
Got the 2 sensors for about 113 bucks from the local dealer and did the repair. FYI, if you do this yourself and look up repair instructions, you don't have to do everything in them as far as removing parts/hoses/etc.!
Took me about 2 hours to replace the sensors, fluid, and then hook up my scanner and clear/reset the KAM.
Drove home and not only is the hard shift from 1st to 2nd gone, the shudder/shake/vibrate issue is also gone!!
Hopefully this helps someone who is having the same issue before they go throwing unneeded parts on their Edge.
Info on my Edge for comparison to others:
2007, SEL, FWD, 190k miles.