Here are a few differences between the N95 and P990. According to the following info the N95 is by far the best phone of the two.
N95 = HSDPA/3G/EDGE/GPRS
P990 = 3G/GPRS
N95 = 99 x 53 x 21 mm
P990 = 114 x 57 x 26 mm
N95 = 120g
P990 = 150g
N95 = TFT, 16million, 240 x 320 pixels, 2.6 inches
P990 = TFT, Touchscreen, 256k, 240 x 320 pixels, 41 x 56 mm
P990 = QWERTY Keyboard, Handwriting recognition
N95 = N/A
N95 = 160MB User Memory + 128MB Card Included
P990 = 60MB User Memory + 64MB Card Included
N95 = Wifi 802.11b/g
P990 = Wifi 802.11b
N95 = Bluetooth V2 + A2DP, USB, Infrared
P990 = Bluetooth V2, USB, Infrared
N95 = 5 MP, 2592 x 1944 pixels, Carl Zeiss optics, autofocus, video(VGA 30fps), flash; secondary CIF videocall camera
P990 = 2 MP, 1600x1200 pixels, autofocus, video, flash, second video call camera
N95 = Radio, TV-Out, 3.5mm audio output jack
P990 = Radio
N95 = Built-in GPS navigation - Installed Maps application covering over 100 countries
P990 = N/A