The lead 30 is a 30 watt solid state analog amp introduced in around 1984
The SL5 is a 5 watt tube amp
Both these amps are based off the JCM800.
JCM800 tones at low wattage.
The lead 30 can usually be picked up at a cheap price, a speaker upgrade makes a big difference and still makes this a great practice amp for little money.
The SL5 is slashes signature practice amp. Great tones at low volume with all tube goodness.
Which one do you prefer?

Guitary stuff from Dublin, Ireland with Phil and Dan😎