A keyboard player doesn't have to relearn or learn a new instrument using a Seaboard.
From a guitarist's perspective the linnstrument everything is upside down and backwards for the left hand. Because I tap everything on the ztar the right hand learning experience has been minimal compared to the left. Yes it's well laid out.
With the linnstrument you have three primary chord "Shapes" It's all 1-3-5 order of notes but you can play that simple chord using three different forms. Once you learn the simple finger origami it transposes across all keys. The three shapes correspond to different fingerings as they would on a keyboard. The same holds true for scales. You have three different fingering approaches starting on the root and ending on the root. In that regard it's easier to learn than say learning the 5 scale positions. And yes easy to transpose across all 12 keys.
What's funny is that I developed several approaches to playing the ztar which...looked flashy and I could play fast/well involving using both hands for "pseudo sweeps/rakes" and more. Since I've gotten the linnstrument I've had little desire to pursue developing those approaches to the linn.
That's not to say I don't have my challenges. I spend a great deal of time trying to develop my left had rhythm and chords/scales. Much more so than my right. If you come from a guitar background and have no tapping experience you'll still play a better right hand then you thought possible
In many ways I wish I could have afforded a Starr Labs ZB2 rather then the linn.
The ZB2 is a 12x24 grid as opposed to an 8X25 grid. The extra octave and a half is the cat's pajamas to me. Yes I can use octave keys on the linn but I'd rather develop the fuller scaling. As well I'm less interested in row slides prolly because of my lifetime of playing bends and slides through various means on guitar. I'm also less interested in up/down Timbre. Although I use both quite often on the linn. The Z board does have velocity and pressure sensitivity Mostly with the ZB it's about the keys. The keys on the ZB are smaller and more rectangular. Which makes spanning the columns and scaling easier.
It also makes for easier organ type gliss as well as spikes and what I refer to as "finger painting" approaches.
They (the linnstrument and the zb2) are apples and oranges. I'm more content with the linn for the most part until I win the lottery and can afford a Zboard.
I've had a lot of fun with the linnstrument and various virtual instruments however I find myself reaching for piano and organ plugins on most days. My goal isn't to run the instrument into a Daw and then mess around with multitrack ideas. I'm not fascinated by that anymore as I've been doing sound on sound and later 4 track recording since the 70's I'm much more interested in "soloist" "Chord/Melody" jazz in all of it's splendid forms.
I´m a strange customer and their patience is very large 
Not sure if even "damaged" keys are included.... 
) ... Roli's 'extra' 2d, strike and lift, are what every one else calls velocity and release velocity, which are supported by many synths/controllers.