We had a lovely week in early April before the main holiday season, so appreciated the beach being quiet with very few tourists. It was warm with some unseasonably hot days (up to 28 degrees). As well as swimming in the sea, we took full advantage of the pool that belongs to the Hermes apartments, a few hundred yards up a slope, with a beautiful view of the mountains. Great to have an apartment on the beach!
In early April there were a handful of tavernas open in Kato Stalos, and enjoyed 'Maria's' (others were due to reopen in coming weeks) and a local supermarket open daily till late. This suited us fine (family of 4 with kids 14 and 10). We visited Chania a few times (a local bus service or taxi fare of 12 euros) and enjoyed strolling around the venetian harbour and old town where there are a host of tavernas and shops selling traditional crafts.
We visited Knossos (on bus from Iraklion) and then Archaeological museum - out of season the museum closed at 3pm, so advisable to visit Knossos early to make time for museum. We had a guide at Knossos, and although quite expensive, brought to our visit an enlivening mix of history and myth, which fired our imaginations. Again, visiting before the main season meant we were crowd free.
We took a Landrover safari trip up into the mountains to where the shepherds go in the summer months - wonderful views, informative and entertaining guides.
We wouldn't hesitate to visit again, and probably at same time of year.