I am indeed happy with it, and I do recommend it if 5 mgp is sufficient for you. I always want to note that I am a member of the Olympus Visionaries group, which means that they provide me with equipment. HOWEVER, I will never say something about the equipment that I don't believe. I have switched from all film - Leica Ms and Nikon F100s - to about 95-98% digital, using the E-1 and now the E-300 as well. I am looking forward to an 8 to 10 mgp sensor, on the other hand, the 5 has given me, and continues to give me, plenty of capability - I have seen three of my 5 mgp images blown up to 30x40 for exhibt and they looked terrific. The camera is built like Nikon and Canon high-end modles costing up to five times as much, is ergonomically ideal for me. In short, it does what it is supposed to do. One thing I will note, however, the autofocus on the E-300 is clearly an improvement over the already good autofocusing on the E-1 - which tells me the next iteration of the E-1 will have improved autofocus capabilities.
BTW - I shoot professionally, mostly documentary/editorial/wedding work, and use the E-1. No complaints from clients.