I've been up that path by Lingmell Beck as far as Piers Gill, nice, but it steepens nastily after that. Also, the path up Gavel Neese or beside Gable Beck to get to Moses Trod is a real grind (better going down than up!). I would be more inclined to take the rising traverse across the southern flanks of Great Gable. To spin it out a bit longer, if inclined, you could take a look at Sprinkling Tarn on the way back, and descend back to Seathwaite down the Grains Gill valley.
There are so many variations, for example - out by Grains Gill, Sprinkling Tarn, Sty Head, Great Gable flank down to Wasdale - return by Lingmell Beck, Piers Gill (the path, not the gully), Corridor Route, Sty Head. A short section of very mild scrambling on the Piers Gill path.
Whatever you do, enjoy your visit!