For 12v, the OP would NOT want the DCF902. It's about 1/2 the power of the DCF901 (1/2" version) and the DCF903 (3/8" version) which are the same tool and both have the same torque, just different size anvils. It appears the OP is referring to the DCF903 with the torque values of 250/400 and 3/8" being referenced. The Torque Test Channel and ShopTools Review websites have videos of testing the DCF901.
The more powerful 20V compacts are the DCF921 (1/2") and 923 (3/8"). If you are considering 20V be aware that the older DCF911 and DCF913 are basically the same power as the 12v 901 and 903 which would probably only make sense if you already have Dewalt 20V batteries and charger.
There were some good deals on the 901 and 903 which included charger and a 3Ah and 5Ah battery for ~ $150 or less. Look around a bit.
If you are looking at spending over $250 or so and want Dewalt, then check out the bigger mid-torque DCF891 which allows tackling bigger jobs. If doing so be careful because the slightly older DCF894 looks almost identical but only has ~1/2 the torque.
I have the 12V DCF901 and it's a spunky little impact that serves my modest needs, but if I had to do it over I'd probably spend more (on a good deal when available) and get the DCF891 with a lot more torque. Extensions and swivel joints can really reduce the torque applied to the bolt. Just my 2 cents. Happy Hunting.