Shwartz expander for upper and lower arch, very slightly uprighted some lower incisors then stopped when I started getting tooth tipping with no affect on weakening the palatal suture, wasted time and money (age 27 at the time.)

@Agendum  What rate did you expand your upper arch?

I dont really remember, I took it conservatively to monitor small changes but it was a slower rate as turning too much just moved teeth within the aveolar bone. I have a vaulted palate + mild torus palitinus which requires more force on the palate. I even tried to sand down some of the parts to distribute force in more appropriate areas (as to not disrupt the teeth too much because of crowding) but was ineffective.

I also ordered an expander, from what ive seen from Mike Mew he suggests to go 1mm per week. He also said that too slow of expansion will move the teeth within its sockets, while semi raped (1mm per week) would expand the skull/ split the suture. On the other extreme "rapid expansion" he said was possibly damaging. Mse is considered rapid expansion and many people have split the suture with it (ie Ronald from jaw hacks on youtube)

@mewgod I currently have MSE and havnt split the suture yet due to having mild torus palatinus, I have to get it reinstalled with corticopuncture. People will have to consider their age and own unique skeletal morphology. People with cases like mine in their late 20's will have little success in removeable appliances and need alot of force to get over the hurdle of a stubborn suture (or vaulted palate that prevents any kind of tongue posture correction.) Generally anyone with space for their tongue can do what acrylic expanders are trying to do though some can move the aveolar ridge/teeth to help get some beginner gains.

@Agendum 

How much does mse cost if you dont mind me asking

I believe the basic expander was about $280 (USD) the last time I got one