I tend to look at an approach to a pronblem with a few questions in mind (in no particular order of consideration or of importance):

a) how likely is the aproach to deliver software that meets the requirements (and has it been determined which parts of the requirements it will meet in an acceptable timescale for an affordable spend)?

b) how easy will the approach make it to start meaningful testing on components when not much of the software is available?

c) are the interfaces between major components of the proposed solution going to be narrow and simple, or will they be broad and complex?

d) how much testing will ne needed and how much rework is likely (c above is an essential prliminary to answering this question).

e) how much can be re-used in other projects

f) how much work is it

g) what are the likely support and maintenance costs

Most of these questions will take rather more than 5 minutes discussion to answer, unless the requirement is for something that's been done many times and has become a standard hadle-churning job or perhaps if the requirement is very simple and clear and doesn't require anything other than very obvious coding.

Frankly, I think the sugested five minute rule is nonsense, and can come only from someone who has been involved neither in software development with a serious research element nor in any development of something with a nontrivially complex requirement. One of the biggest and most comment management faults is to build plans with insufficient time for design, and for getting to understand the requirements, and for determining how adequate testing will be achieved. Many design discussions, discussions of testing methods, and discussions of interpretation/clarification of requirements need far longer than five minutes. One important point is that it will very often require more than 5 minutes (a lot more than 5 minutes) to get a reasonable guess as to which approach will be the easiest to implement

Dogmatic arguments about methods based on personal preference/prejudice are of course a different kettle of fish; they shouldn't happen at all. A five minute rule is unacceptable there too - a 30 second rule might be acceptable but a 10 second rule would be better.