If ICS seems slow you should do a Factory Reset first before anything more extreme like trying to go backwards to a previous version.
The same things were happening when the Xoom was upgraded to ICS......a few had issues with it feeling slower while the majority were raving about the increased performance. A Factory Reset corrected the slowness and/or FC's on most of those.
I personally always Factory Reset when changing/upgrading ROM versions (Eclair to Froyo, Froyo to Gingerbread...and now Honeycomb to Ice Cream Sandwich). Seems to keep the issues to a minimum.....
(just purchased a Transformer for my wife....)
Motorola Droid - SnkBitten 2.2.6 - Froyo 2.2.3
Motorola Droid 2 w/root - GB 2.3.4
Motorola Droid 3 w/root - GB 2.3.4
Motorola Droid 4 w/root - JB 4.1.2
*Motorola Moto X DE - KK 4.4*
*Google Nexus 10 - KK 4.4*