Martin,
The route from Snowdon to Lliwedd (Watkin Path) is quite a challenge, especially if you have to retrace your steps to return to Llanberis via Snowdon again. If you choose this pairing you may want to opt to continue back down the Watkin Path to Nant Gwynant and get a bus back round to Llanberis.
In March I did Lliwedd, Snowdon and Aran in a day but it took about 10 hours and was cripplingly tough for a lightweight like myself ;o)
Michael
