[RTTY] USB Rig Controllers - are they reliable?

[RLVZ at aol.com]

Whew- great band condx this weekend made the JARTS RTTY contest a  blast.
 
I'm thinking of purchasing a USB "Rig Control Interface" such as  the 
HamLink USB by Timewave Technology or the Rigtalk by West Mountain  Radio.  Does 
anyone have one of these operating reliably while  operating RTTY at 1.5kw?
 
The reason I'm thinking of trying one is because rig control via  my serial 
port is unreliable as I lose control of my radio  occassionally... even at 
times I'm not  transmitting.  The mother boards built-in serial port must  
be defective.
 
Do you recommend I add a separate serial card or go with a USB Rig  
Controller? 
 
THANKS & 73,
 
Dick- K9OM