Roadster or Road King hands down. People re going to disagree but I can get my Road King very close if not dead on to the Mark V channel 3 Liquid Lead sound with 1 OD pedal and proper EQ (chopping out the Bass frequencies for instance). I am going to do some videos this week of the new rig. I was able to have both amps together for a day or so and AB them. I have played a Roadster several times at Hollywood MB Store. FWIW My Mark 5 was a combo with a ported 1x12 MB cab and had the stock tubes in it. I had it for 2 months before trading out to the RK2 last week.
If you like to switch power tubes around and have every option under the sun (well almost...) - RKII is 4 U
If you can't live without that Mark IV sound and you need that Great Mark 1 Santana tone without any pedals - Mk 5 is the amp
If you are going to use pedals or OD's with your amp anyway - Roadster or Roadking by far
The clean sounds are equal (pretty much) on all 3.
MARK V PROs:
Lightest of the 3
Tightest sounding of the 3 (almost to a fault - for me anyway...)
Well designed Foot Controller
Has the classic Mark 2C+, IV and Mark 1 sounds
May be able to pick up a used one at a discount
CONS:
I felt the amp was a bit disjointed between channels 2 & 3
Mark 1 is very dark. Good sounding - but there needs to be more play in the tone variation control there for me
The rest of channel 2 is really stiff feeling and somewhat THIN sounding compared to the MARK 1 setting - which is great if that is what you like.
Going from Mark 1 on ch2 to Mark IV on Ch 3 is just bizarre. Your bass goes away - it sounds honky and mid-rangey and you wonder why Mark 1 is not the Lead channel. This amp has basically 1 CLEAN channel and 2 LEAD channels for live use. And switching between them isn't like changing sounds - it's like changing bands.
CH 2 Crunch setting takes pedals well but not a lot of variety there compared to the 2/3 channels of the RK2.
Channel 3 is all gain all the time. And I felt each setting in CH3 did one thing well and found the other settings not for me.
This amp is very good at what it does - but it feels off when you compare the two side by side. I loved it until I had to make it work in a band setting. Then the M5 sort of showed its limitations.
RK2 PROS:
Very versatile
Almost endless possibilities of tone
Fantastic FX Loops (2)
Very easy to dial in - and BALANCE - every channel
BRIT Mode channel 2 is the ****.
Every pedal and guitar I have sounds good through this thing
You want Mark IV LL ?- Channel 3 - DIODE rectifier - Gain at 1-2 - treble up to 3:00 turn down the bass - Mids to taste - use a BB overdrive or similar depending on the guitar. For my Stratocasters with hot rails PUs in the bridge there is almost no difference between the 2 amps at that setting. I'm sure the purists will disagree but I was satisfied. Then again I'm not playing Dream Theater or Masters Of Puppets covers. Not that there is anything wrong with that...
ROADSTER PROS:
Sounds every bit as good as the RK2 and just as easy to dial in
Cheaper to buy
Cheaper to retube
CONS:
These amps are heavy as ****. Seriously.
I get pops switching channels every once in a while - nothing major
That King Foot controller is a real long piece of real estate
IF you are in love with the Mark sound - you'll have to dig a bit to get it.