There isn't two classes of MSPs though. That's your (and some others) personal perceptions. The parliament is 1 member 1 vote and list MSPs can represent their constituents interests (lol) hold office or fulfil roles just the same.
STV is more complicated and would piss people off. The ballot papers could stretch to pages and pages and I and others cannot be fucked drawing a cock and balls multiple times.
130 giant constituencies is madness I'm afraid unless you think hampering or preventing smaller parties and independents running is a good thing due to the increased cost of travelling, campaigning and canvassing. Especially in Nothern Scotland, where the spread of population is so thin, which would make almost everything north of the Central Belt and Perth/Dundee into 1 or 2 constituencies.