The LB5 is a cleverly designed (with a beautifully finish!) module dedicated to logic functions. It allows very creative patching. I own one and no other of my modules can replace it. The Disting mk4 is a good Swiss army knife, it allows more or less to temporarily compensate for the absence of this or that functionality. Currently, for example, I use its delays a lot... while waiting to buy a true delay module like the Chronoblob.
'On ne devrait jamais quitter Montauban' (Fernand Naudin).