We've only been to the Dingle Peninsula once so can't comment in a compare and contrast way from a personal point of view but there's certainly plenty of hiking to be done from Clifden - read this article for an insiders tale:
away.com/tripideas/clifden-county-galway-hik…
There's lots of walking on the flat (eg. Roundstone Bog) and gently sloping roads (you can walk the Sky Road) and coastal hikes to places like Mannin Bay that can be done from the town itself and there's a lot of mountain hiking in the Twelve Pins/Bens and Maum Turks ranges that can be accessed by an organised hike from the Connemara Walking Centre in Clifden. The resident host of the centre is field archeologist and historian Michael Gibbons (brother of Mary who organises tours from Dublin) and his guided walks and hikes are excellent:
www.connemara.net/words/article.php?id=075
http://www.newgrangetours.com/
Connemara Walking Centre
Archaeological and heritage walks, tours for groups and private bookings.
Michael Gibbons, Island House, Market Street, Clifden
Tel:095 21379
walkwest@indigo.ie