@silicon
Well, I believe it to be one of the best racing experiences on a portable console, but it depends on whether you like a more fast paced racing experience like WipeOut or Need For Speed, or you like a more simulation based racing experience.
In GT PSP you can play almost in both styles, since if you drive on the standart car physics, it will be very arcady, and if you put it on professional, you'll have a heavily sim based experience.
Other thing to consider is that the main soul of this game is to collect all the cars for GT5, since everything in this game will give you a huge amount of money for that same purpose, which, in combination to what I said before about the unlockables, will have you playing it for a long while. Heck, I completed almost all driving mission challenges with gold, but i only got 17 cars from the 800 pool, so you see how long I still have to go on the game ;)
Current PC Build
CPU - i7 8700K 3.7 GHz (4.7 GHz turbo) 6 cores OC'd to 5.2 GHz with Watercooling (Hydro Series H110i) | MB - Gigabyte Z370 HD3P ATX | Gigabyte GTX 1080ti Gaming OC BLACK 11G (1657 MHz Boost Core / 11010 MHz Memory) | RAM - Corsair DIMM 32GB DDR4, 2400 MHz | PSU - Corsair CX650M (80+ Bronze) 650W | Audio - Asus Essence STX II 7.1 | Monitor - Samsung U28E590D 4K UHD, Freesync, 1 ms, 60 Hz, 28"
