any arguements for getting a JCM800 over the 1959SLP?
Versatility?
You cant go wrong with either IMO, its a rock vs HARDrock issue, the JCM has never let me down EVER in the 12 years i have it, i even wouldnt be surpriced it still has the original tubes. The clean channel on my JCM800(arguably less full sounding) is not as nice as the 1987 (both 50w's) but then again i like the cleans on my Bluesbreaker better then the 1987. I personaly prefer a 50w marshall amp over a 100w one, i use greenbacks which dont work well with 100watters IMO.
Like always, i cant stress this enough, try to get a decent original one first, might cost a bit more but when i see my JCM800 has doubled if not tripled in value you know why i say this. Plus the fact offcourse that a well kept original will trash any reissued one. In terms of reliability i allways found the old players werent as prone to cranks and quirks then a new one, this again with a well kept amp, i think anyone buying an old marshall should calculate a good TLC on arrival.