I'd say its an indication of your Peavey cabs inferiority, but the Line 6 cabs are cool, IMO.
To be clear, there have been 3 Line 6 4x12's over the years, and narrowing down which one you used may indicate what you liked about it. The first 4x12 they had were loaded with Eminence speakers. They were part of the Flextone series, and they had the red/silver grillcloth, and a oval metal badge on the top of the cab, in the center, with the flextone logo and a rhino or elephant style tolex. When the Vetta came out, Line released the "vetta" 4x12, which featured custom Celestion speakers made for Line 6 and the softer leather look tolex (more like Mesa tolex), black grill cloth with white piping. With the release of the Spider Valve series, Line 6 came out with new Spider Valve cabs. They are loaded with Vintage 30 speakers and are Chinese made. The construction of the Spider Valve cabs look REALLY close to Bogners (a larger rolled edge around the baffle with no corner protectors is the most notable feature), and I'd say the design and dimensions are ripped from Bogner due to the connection with Bogner for the SV series. They are killer cabs and waaay underrated. I'm assuming the Chinese made SV cabs continue in the tradition of the Vetta cabs before it with baltic birch ply construction, but I don't know for sure. The smaller budget series Spider cabs suck ass, so I doubt you used one of those.
I owned a Vetta 4x12 for over 3 years, and it was a killer cab. I ran it in tandem with my Recto cab when I played an HD147 and it killed. I'd argue that the custom Cele's sounded better than the V30's in the Recto for that amp head, but both cabs had their strengths.
If I were to assume or guess, I'd wager that the cab you used was a Flextone or Vetta cab basically due to the amount of time they've been out and the fact that it was provided by the venue...For some reason, I don't see them providing a cab with V30's that's not been out too terribly long.