i have extensive experience with all of the amps you mentioned in addition to a mark v from mesa.
the jcm 2000 model will be the cheaper of the bunch and sounds great for the classic marshall tone.
the jvm 410h is a head I own....i dont actually own the new JS model but based on what i know from my head and my knowledge of the changes to the JS model it will be more expensive and alot more versatile. the built in noisegate on the JS 410 is a super nice feature......and until you actually play a JVM model it's hard to comprehend the MASSIVE amount of gain these amps have on hand......no pedals necessary to juice that bad boy up.
the dual rectifier is a bone crusher and does the hard rock and metal thing very well. as much as I like it i prefer the mark v head over it because it is more versatile and even though lots of "metal" players use the mark v i think it's a fabulous amp for getting just basic hard rock, rock and country tones. the wattage switches are nice on the mark v as well.
overall, if money is an issue then the DSL may be your choice......if you are looking for the most gain with versatility then the JVM.........because it not only has the channel choices but it can be channel changed via midi.
I am a huge Mesa guy and i love all of their stuff.....it just sounds different than Marshall.....apples and oranges to my ears.....if you like the way a Mesa sounds better than a Marshall then that's the right choice for you.....and if you do you cant go wrong with the dual rectifier but i would give the mark v a serious look.
any traps to watch for with these models????
