If I remember correctly, the lower voltage will cause the batteries to drain faster. Though someone that knows these things will probably correct me on that one. 
I've been using Fusions for the last week or so... and I like them a lot more than than the Boges. They seem to be lasting longer, as well, in a tank. As Ruppy said, you need an adapter, but it works well. On an 808 cap the adapter is about the same height than a 510 top cap. Stacked on a 510 cap you'd have more height using an adapter. (Pictures of it here at post #834 and Bovinia's here at post #852.)
The Boges are perfectly good, of course. I'd definitely try the Fusions if you can, though. Well worth it!
+1 on the IKV io6. Best drip I've come across. Comes in 2.5 and 3.5 Ohm versions. Both work great on the Buzz Pro. I've been enjoying their Stealth series 901s a lot, as well. Haven't used any other attys in months.
I've been using Fusions for the last week or so... and I like them a lot more than than the Boges. They seem to be lasting longer, as well, in a tank. As Ruppy said, you need an adapter, but it works well. On an 808 cap the adapter is about the same height than a 510 top cap. Stacked on a 510 cap you'd have more height using an adapter. (Pictures of it here at post #834 and Bovinia's here at post #852.)
The Boges are perfectly good, of course. I'd definitely try the Fusions if you can, though. Well worth it!
+1 on the IKV io6. Best drip I've come across. Comes in 2.5 and 3.5 Ohm versions. Both work great on the Buzz Pro. I've been enjoying their Stealth series 901s a lot, as well. Haven't used any other attys in months.