The LB1's are great but small monitors.
They are quite popular in my circle and I am quite fond of them.
One of my first encounters was at the Sadie office, a 5 channel surround set linked to a simple Sony amp and it blew us away!
Later at the Sony SACD office we did a comparison of LB1's to various ADAM models, 2 or 3 of two way ribbon tweeter models, and the LB1 won.
Very nice top end and integration from low-mid to highs. The sound stage is very convincing and appealing.
But I wouldn't use them for mastering, not enough SPL, the woofer can actually break from high levels. The build quality is not very sturdy, not at all like its bigger PMC brothers.
I do use them as home system and they function well for checking work brought home from the studio. They are combined with a B&W sub.
In the studio of the Bimhuis in Amsterdam where I also work we have a set of LB1's combined with the PMC active sub. The sub is a great extra and takes a lot of load of the LB1's woofer. In total there is more level and a far more relaxed sound at higher spl levels.
So: get them! and look for a Bryston 3B (ST/SST if you want).
I'm sure you can use them somehow, maybe not as your mains though.
