I have not used the B&W one before. But I did used the IR Slides. These are my experience:
1. Best to keep unexposed film in the fridge
2. Load film in total darkness
3. Bracket your shots. The slide ver have got very little exposure of approx +/- 0.5 stop only
4. I din have problem with focusing cos I used all wide angle shots. But I understand that you may need to use some de-focus technique when shooting shallow DOF.
5. Try to process your film ASAP after you have shot. Aviod Heat.
Eh...these are my experiences with IR Slide. Hope its useful to you.