It was decided by the developers of the game that TWF was extremely overpowered. This plays well because the pysics check, made .15 sec after the main hand of a TWF supposedly is responsible for a some of the lag. By removing the opportunity to use your offhand with a % based system vs a static number of times, you will generally get fewer chances to use your off-hand, lowering effectiveness of TWF. The removal of the second physics check was to address some but not all issues of lag.
This effects quite a few people across the board. Both new and those that have played for several years equiping and building characters based on the in game mechanics.
The only thing I can suggest is if you can access Lamania, do it. Review the combat situation and feel of gameplay. And post your findings here.