I don't see much how you wanna tackle this question by just dropping a framework like that. I think it something really case/context-specific.
So, regarding a general metholodology, here is what i would do:
(0. If the solution hasn't been previously mentioned, stall and ask questions to make ure you understand.)
1. Take a new sheet of paper. Draw a quick table with 2 columns ("Adv" / "Disadv.")
2. Fill in the columns. Start with the advantages (in my experience, that's easier).Then fill the disadvantages.
If it is coming in the middle of case, you should have elements in the data already studied / in your framework allowing you to answer. So look at it !!!
3. Rank these items : What is the best advantage ? What is the worst disadvantage ?
4. Make a conclusion : does it seem good or bad ? Where should the client focus ?
There is actually two ways of applying this :
1. You feel it is just a quick question on the go, in the middle of a case, so you just apply that methodology quickly and speak as you write.
2. You're lost, you feel it is a big deal, or the interview is starting with it. Don't panic. Ask a for second to write down your thoughts. Do Step 1-2-3 on the paper and then explain directly your list and hierarchy of adv. and disadv. Then conclude.
Hope it helps a bit !