The brother basically plays the third guitar in the first two albums and the second guitar in Rainbow and BBC.
David is not a super guitarist but in the first two albums together with Mark who plays the second guitar he does an excellent job, the sound is well integrated, blended. Perfect.
Not very decisive in the two live but good.
Hal Lindes in Alchemy is undersized by the recording. Difficult to give a judgement.
Jack Sonni comes out well in San Antonio performance. Very integrated in the sound and rhythm.
Phil Palmer, certainly a great guitarist, in OtN doesn't convince me, very rhythmic, but not innovative. He doesn't leave his mark.