I have a 4101 (1991), it's a very versatile combo. 100W means it's seriously loud. The penthodes in the poweramp (EL34s in my case) are just so powerful that they remain relatively clean at lower volumes.
I can get really close to a Carvin Legacy tonewise (compared to the samples on carvin.com) Hendrix stuff is also easy, they are very responsive to dynamics as well as your volume pot. I don't know much about the DSL100, but you may also want to have a look at the anniversary series. The 25th (25xx Jubilee) is very sought after, but you may run into a 30th (61xx)
A lot of rubbish is said about "diode clipping", Marshall started using this in some of the JCM800, those & the JCM900 dual reverb use hybrid cascaded gain stages. This even applies to the Jubilee and Slash signature JCM800. The JCM900 has a preamp with op-amps, a boost channel with diode (LED!) clipping and pre-boost EQ into tubes, with semi active EQ powered by an ECC83 (for more info check http://www.thinlizzy.de/Guitar/earlymarshalls.html
or look for the electrical schematics at http://www.drtube.com/marshall.htm
The JCM900 has three ECC83 "preamp" tubes, only one is actually used in the preamp (but it's used as a double triode giving you two gain stages)
The second is used (again as double triode) as reverb driver and after reverb recovery
The third EEC83 is used in the power amp section. Each triode side driving a pair of EL34s.
I think the advantage of these pre-amp solid state circuits is that you can easily reach hi-gain sounds, at the expense of sounding a bit buzzy at lower volume (without power amp warmth added) In fact using a typical distortion box (RAT, Fuzzface, Tubescreamer, OD1, MT10 etc.etc.) into a pure lo-gain tube amp gives you a similar thing.
Even with the partially solid state hi-gain channel it doesn't quite reach extreme gain in JCM800 or 900 (supersaturated perhaps) This is probably why they came out with the SL-X. If you want an over the top metal sound, I still would suggest experimenting with an additional pedal and/or an active EQ in the Fx-loop. The first thing your guitar signal will see in a dual reverb is indeed an op-amp so overloading the input will give you clipping in that circuit before you even reach the gain stages. In master volume amps the first thing your signal will see is a tube. If you plan on using an overdirve pedal, these may have an advantage.
I have to admit that I rarely use the pre-amp section on mine, I use it as a power amp with my GSP2101 on preamp duty. Buty that's for flexibility not because I don't like the sounds of the JCM900.
Most people agree that the best sounds are generated when you start pushing the power tubes (EL34s or 5881) which is difficult in a 100W amp without scaring the neighbours. Switch to half power (triode mode) or use a powerbrake/loadbox.