The cabs are solid, with metal handles, I owned both the V30 cabinet and Eminence L.J. speaker loaded cabinets since the mid 90's used both at the same time on stage for 4 years and 2 of those years I was gigging 5-7 nights a week..
Got tired of the V30 cabinet sold it to some one to use in their recording studio, Year later they still have and still using it..
I kept the Eminence loaded cab due to liking the speakers more because they didnt break up as early as the V30's..
Then I reloaded the cabinet with Wizards and I am even happier with the cabinet now..
Not much experience with the XLA head since it didnt have seperate Eq's for each channel but I owned 2 XLS's with my 2 cabinets..
Sold the 50 watt head last year to some one and kept the 100 watt head it isnt going any where..
I gigged with it heavily along with the cabinets.. No problems ever them..
Even without the heater mod..
The only issue with the heads is you need to do the Heater Mod which you can look up on Lee's web site..
My 100 watt head I suspect needs a cap job due to being stored and not played for 7 years or so..
http://www.leejackson.com/Questions-Answers/