[A/S] Anyone use Trojan Batteries?

[Chuck H <funchucky@xxxxxxxxx>]

Anyone have an opinion of Trojan batteries?
I'm thinking of getting a couple of them, the 6 volt
305's.
How about using them in series for 12 volt?  Any
problems to expect doing that?

These are pretty big batteries.  Designed for use in
big floor sweepers, originally.  Heavy duty deep
cycle.
I'm not sure where I'm going to put them just yet, as
my older Avion currently has NO place for them.  I am
aware of the need to isolate and vent, etc.  

Any problems charging these, that anyone knows of? 
Should I use a 12-volt charger in series?  Or get a
6-volt charger?  Is one way better than another?

Anyone with experience?
Thanks in advance!
-Chuck