Hi, L. Chung,
I think you missed the last part:
"No problem with lag, except for, wait a minute, one little thing. Is it a good idea to put a lag in the feedback loop? If you have a 30 MHz op amp and you want to cancel the lag with the 30 MHz op amp, putting a lag in the feedback is not necessarily a good idea. I went out and got some of these op amps. Well, it’s not a disaster; it’s a caution that when you actually build it, you look and it shows you can see the ringing at about 22 MHz, with a Q of about 2.
Now, if you don’t mind that, you could probably use the circuit. You know, it probably won’t oscillate. But I’m nervous because I don’t like things that ring that badly. I think this approach would work better. If you've got to use a reasonably quick op amp, use an R and a C. This has a lag. You want to put a lag in the feedback. Let the capacitance here give you the immediacy so it don’t oscillate."