Which is a better driver, Vifa or ScanSpeak?

[inmypjs]

<font color='#000000'>Any DIYers around here who use these drivers either exclusively or in combination. &nbsp;What is the best crossover to use with them. &nbsp; Did you use a GR Research designed crossover? I'd like to hear your experience.

Vifa Kit
Scan Speak kits
The Ariel
GR Research</font>