As I've written here before, I believe the iPhone to be the best cell phone I've ever used. I started out with Nokia phones and kept with simple Nokia phones until I got my iPhone. I loved Nokia, they seemed bulletproof, had great sound and grabbed even the weakest signal. I tried out a Motorola Razr, but was totally disappointed in it's performance. My kids have had numerous brands of phones from Motorola to Samsung and I just haven't seen much quality.
When I got the iPhone, it took a little getting used to. Speeds weren't all that great and the firmware seemed a bit...quirky, I guess would be the best way to put it. One thing that I noticed was with 3G turned off, I got the best signal reception I had ever gotten, even beating the various Nokia models I had used. Notice that I had 3G turned off. Until the first week of January, AT&T's 3G network was non-existant past just a few miles away from downtown. I coped, though, using the EDGE network for data when I wasn't around a wifi connection. According to this article, most of the iPhone's speed issues could be traced to AT&T's network.
BAM, the week after Christmas, I'm messing with the iPhone. Hmm, let me just check out the range of the 3G network. WOW! We're pretty much covered up with 3G around here now! I love the increased speed. The iPhone, while always a thrill to use, became even better and has fulfilled all my expectations now.