Major and minor triad arpeggios can be used to great effect in solos in a variety of ways. They lend themselves to thematic playing, and can be used to reharmonize chords in a way that is easy for the player to conceive and the listener to hear.
Sounds great to me! Where do I sign?
Hold on a second.
The catch is: triad arpeggios are challenging to play on the guitar. This can be overcome with a little practice, starting with this exercise:
Play this triad on the D, G and B strings first; then the A, D and G strings. Practice this with a metronome so that you don't slow down on the difficult parts and speed up on the easy ones. I would start with quarter note = 60.
On the G, B and E strings the left hand fingering will be completely different:
After practicing on three strings, add the octave on top (for the lower fingerings):