My 610HLF is from May of '06, and i've been using it for 4 years solid with no problems at all. It is possible that mine is from the chipboard era, but as i was told, if it's never in a flood i should be ok. hahaha.. But seriously, it's a great cab, but is sonically different from the 810. For my ears you need to stand away from the 610 about 10-15 feet to really hear what it's doing as opposed to the 810. 810 = more punch, 610HLF = more bottom end. The front ports on the 610HLF seem to disperse the low frequencies more than the sealed, punchy 810. IME at least..
Having used both for some years, i have to say i like the 610HLF. Easier on the back and sounds great. YMMV tho...