I would add one further thought to this discussion:
Having your amp and monitors in the same box is only asking for trouble from a pure convenience perspective: if one or the other breaks down or gets fried you to do without both whilst repairing or replacing the damaged part of the system.
Having them separate means that you can survive if one or the other is out of action simply by having a spare of either either hired or bought.
And deranged is right, this move to integration is crazy and was never designed to actually be of benefit to anyone except the manufacturers: your amplifier is burnt out, it will cost $ZZZ to replace the damaged component, but for less, or maybe just a little bit more, you can buy a new integrated unit: in either case, it's a no brainer for most folks: you buy the new unit.
If you have separate components, then replacing an amplifier is usually not as cheap as getting the repair done unless you are chasing hard to get components (Foggy has some stories to tell on that front). If you have a blown speaker, it is cheaper to consider
re-coning (replace the cone/spider/voice-coil combination if the cone/voice-coil is damaged) or replacement of the whole driver if available
An additional thought for all - most hi-fi speakers are only capable of achieving 1%-5% conversion of the electrical power fed to them: i.e. if you have 100w RMS electrical rating on the output of your amp, the speakers are only producing the equivalent of 1w-5w of acoustic power.
For djing, this may not be optimal and so you should consider horn-loaded cabinets that improve efficiency to between 30%and 50%.. In addition using several different types of horn-loaded cabinets designed for different parts of the frequency spectrum (3 boxes per side (W/sub, mids, highs) are the usual here, though some folks will go with 4 (W/sub, low-mids, upper-mids, highs)) I would also drive these boxes with separate amplifiers to maximise frequency reproduction. You can still get all of these into a small van or station wagon and have room for passengers.
@Salem: Nice references to the NS-10's (which were then slightly redesigned into the MS-10's - mostly cosmetic rather than electrical or or cabinet design) and the Auratones (Radio Shack/Tandy had their own version of these at 1/10 the price in the late 70's/early 80's).
And you have hit the nail on the head, no-one wants to go old-school because old-school is unhip for most new producers - they don't want to study the past for any reason so of course are doomed to repeat the failures that everyone who has gone before them with the same attitudes has already achieved - when big-names start prosletysing about the benefits of tried and true gear and approaches then maybe our beginning brethren will accept that there is something to it; until then, we can but point the way and point out the errors of their ways.
