Your title says progressive, but the body of your message says interlaced (60i) so what are you actually using?
More information needed for someone to help... click these links and provided the requested information
-http://forums.adobe.com/message/4200840
-http://forums.adobe.com/thread/416679
As far as the slow & choppy, you need a STRONG computer to edit AVCHD
Some ideas for a Desktop Video Editing PC
http://www.adkvideoediting.com/
-ADK Kudos http://forums.adobe.com/thread/877201
.
Build http://forums.adobe.com/thread/947698
-more build ideas http://ppbm6.com/Planning.html
-Build it Yourself http://forums.adobe.com/thread/815798
-http://www.shawnlam.ca/2012/premiere-pro-cs6-video-editing-computer-bu ild/
.
Some ideas for a Laptop Video Editing PC from past discussions
http://www.sagernotebook.com/
http://forums.adobe.com/thread/957472
http://www.adkvideoediting.com/
.
For effective HD video editing, a laptop with the following
-at least the Intel sandy bridge 2720 or 2820 quad processor
-and nvidia graphics preferably the 460m, 485m is a bit much
-1280x900 display with OpenGL 2.0-compatible graphics card
-and 8 or 16 gig ram and Win7 64bit Pro
-and 2 internal 7200 HDDs minimum
.
This message has a really good graphic about requirements
CS5 Requirements http://forums.adobe.com/thread/810750
About Requirements http://forums.adobe.com/thread/618058
Disk Configurations http://forums.adobe.com/thread/878419
