Hi, Chris!
Yes, I went to Ierapetra. And I liked it.
Advantages: It's a (albeit small) town, so everything (banks / cash dispensers, internet cafes, pharmacies, supermarkets) is there multiply, so you don't have problems when one fails.
Car rentals are pretty cheap. One car rental agency had a special offer at €90 for four days.
You see a bit of the locals' life (like, for example, when Olympiakos won the championship). It's not dominated by tourism.
Disadvantages: The local beach is not very nice, so you need a ride (if you don't want to wait for the bus). Which leads us to the next problem: motorbike rentals are expensive. Well, they got more expensive in all of Crete (as I mentioned in earlier posts), but in Ierapetra they're specifically pricey.
The beaches east of Ierapetra are quite nice though (especially Aghia Fotia and Ahlia).
If you live along the main road be sure to have soundproof windows, as moped traffic usually lasts until 3 a.m. I usually get used to noise like that because it's Greek noise, but it may hamper your sleep now and then.
Restaurants are slightly more expensive than in Plakias, but no more than about 5%.
Room rates are about the same (we paid the exact same price for our rooms in Ierapetra and Plakias).
The tour to Lassithi was dropped due to 1) laziness and 2) rainy weather inland.
We did roam along the coast a bit, nearly got lost in the olive groves below Aghios Ioannis (very labyrinthic there) and went to the Butterfly Gorge (although I squashed more butterflies on the freeway on our short trip to Croatia this weekend than I saw there).
We did a boat trip to Chrissi island. Quite nice (especially in early season when the umbrellas are still there from last year but there's noone there to collect money), but the boat fare is way overpriced: €20 per person for a 3/4 hour trip. It was OK though, because on Chrissi the sun was shining whereas on the 'mainland' it was cloudy.
All in all, we really enjoyed it, but we were glad to spend the rest of the holidays in Plakias.
Andy