12dB Bessel VS 12dB LR?

[diyiggy]

Hi,
What are the pros and cons to use a Bessel 12 dB slope crossover over a 12 dB Linkwitz- Riley, please ?

Does the Bessel need a physical offset when made passive like the LR ?

Does the Bessel exhibit better group delay if used for a bass to woofer driver cut off ?

What about the off axis when used for a tweeter ?
Can we use one for the low pass and the other for high pass without problems ?

Thanks