Boat Diving at Buddy is a bonus in that Klein is not accessible for diving any other way.
The Diving from the Boat at Klein is in most cases very close to shore; often dropping in at ~20-30 feet.
Sign up on the Blackboard at the doc is simple but don't assume that space will be available last minute.
When we were there I was quite disappointed that all the 3 Tank Dives to the Northern part of the island were cancelled due to the volume of groups visiting at the time.
The DM's at Buddy that manage the dives are excellent. Relaxed approach in most cases.
Timing of dives during the day is very nice. 8:30 for a dive back at 10ish allowing to join the next dive. Dive in the afternoon. Overall lets you explore the island and shore dive while at the same time get some off shore variety.
As I understand it staying at Buddies a certain number of boat dives are included in the cost. I've been told you can "trade in" these dives for alternate activities - caving for example but I have never explored this option myself.
All the dives we've done on Klein have been excellent. Buddy also does a dive to Hilma which saves the swim out which is a bonus from an Air/Gas perspective.
Buddies boats are in great shape and easy on and off with a good deal of room to "get ready" and they limit the number of divers I believe to 16.
Have I missed anything?