Can you explain to me the differences between the two types of L-Pad configurations.

Type I: "Traditional" type with R-series followed by R-paral and driver.
Type II: "PI" type with R-paral followed by R-series and driver.

From what I see, Type I is much more sensitive to resistor values when high levels of attenuation is required and also requires very low values for R-paral, which are hard to find.

Type II seems to be more "stable" and tolerant of resistance variations and uses easier to find values.