The 7M is as good as any, and can be as good as the 2JZ. The reason why the 2JZ is better is because of what it comes with in it's stock form.
First off, Toyota learned with the 7M, that the torque value on the head was wrong, and increased it on the 2JZ, in other words, they fixed the BHG problem with more torque.
Second, the 2JZ comes stock with forged pistons. This means you can run 500+ hp on stock internals
Third, the 2JZ comes stock with 550cc injectors, the 7M only 440cc.
Fourth, the twin turbo setup pushes more air than the ct-26
Fifth, the MKIV comes with a more efficient intercooler
Now, of course the overall design of the 2JZ is better than the 7M, but that comes with technology and improvents, such as a better oiling system, and better flowing head.
Now, if you port a 7M head, and drop in a set of 2JZ valves, run forged pistons, larger AFM, larger injectors, 2JZ IC, and get an upgrade on the ct-26 to push more air, at the same boost as a 2JZ, the 7M's output will be equivelent to the 2JZ.
They didn't stop making the 7M becuase it was a bad motor. They stopped because they made someting better to replace it.
And like Santerianumero1 said, I did his 7MGTE swap for around $1,500. This came with a rebuilt motor, and a port an polish on the head. As soon as the motor was rebuilt, the swap only took 1/2 day. Hmm, probably a little easier than a 2JZ. Problem with the 2JZ, is that the turbo's won't fit. The strut tower is in the way. So, if you ever plan on doing a 2JZ swap in a MKII or MKIII, plan on going aftermarket turbo with custem header manifold, or move the engine over to the drivers side(I have seen this done before in a MKIII, looked like hell) Aslo, to fit the getrag V160 6speed, you will more than likely have to cut out the tranny tunnel. The 6 speed is much bigger than the W series tranny.
My opinion is stick with the 7M. It is a good motor. If it is used, replace the HG, resurface the head, and torque it down to 72 ft lbs with some ARP studs. Unless you really overheat the motor, you should never have to deal with a BHG again.
7M not being a good motor, BLAH!