its been a few months since i bought my nexus one at launch. so far i must say that i'm very satisified with my purchase and believe it can almost replace an iPhone.
however, lately i've been dabbling into the custom rom scene and am loving the MoDaCo ROM Desire Port. SenseUI is basically just a skin for Android made by HTC Its available on their Windows Mobile phones and also select Android phones. The HTC Desire is one of their latest phones; its basically like a Nexus One except for an 8mp camera and digital trackpad vs trackball.
Since the hardware is nearly identical, porting of the Desire's SenseUI rom to the Nexus One was just waiting to be done.
I've been using the MoDaCo Custom ROM r21 and so far have had good luck with it. There are some bluetooth issues but i never use bluetooth. Battery drain is def increased but can be fixed by using a custom kernel (i'm using persiansown latest 925mhz cfs kernel.
Here's a quick video of my Nexus One running the Desire Rom. (please excuse crappy sound, got new camera, 720p vids and stereo sound in all new vids)