I like to keep "simple" investments as uncomplicated as possible. Googling this subject suggested that brokered CDs could give higher interest rates due to their negotiating power. A couple of years ago I called one of these brokerages and found that their GIC rates were inferior to what I was able to negotiate with my bank. I think it helps that I am a loyal customer.
Well, brokered CDs can have a great place in a portfolio (and perhaps GICs in Canada vary a bit more regarding yields and complexity compared to brokered CDs in the US?):
--Estate death put feature: I placed all of my grandmother's investments into various brokered (FDIC-insured) CDs, all of which had the death-put feature. The best part of this is that it permits the estate to either keep/retitle the CD, OR redeem it at full value, at the option of the estate. When she passed in 2011, I elected to retitle a 5.5% fixed CD with at least 3 years left until the first callable date, and promptly sold it for well above par. The other CDs, we elected to redeem. I don't know if many banks would go through the hassle of retitling CDs to heirs (or even if they permit it), or would simply require you to cash them all in.
--Higher average yield: Because a bank can issue several million of CDs in a short time with relatively little expense, they can offer higher rates. Of course, these higher rates sometimes come hand-in-hand with different conditions (see next point).
--Conditional rates: While one typical downfall of many brokered CDs is that they often be called by the issuer after a certain date, they sometimes have various rate formulae that you can use to hedge. For instance, one CD I put my grandmother into was a 20 year CD with a fixed rate, and it paid out interest as long as LIBOR was less than 5.5%. This allows you to lock in a relatively higher rate (at the time), and if rates stay low, you still get this decent yield. If rates jumped up an insane amount, then you might get zero interest - but I really didn't see that happening within 5 years of her buying the CD (and given her age/health, if she did live 5 years, her zero interest on a relatively tiny CD would have been worth the extra time she had).
Along this line, in 2008/2009, some brokered CDs also had very generous first-year guarantees because the banks were trying to increase cash on hand (like several Bank of America and Bank Hapoalim CDs), sometimes with juicy rates of 7%, 8%, and even one at either 8.5% or 9%! The equation after the first year was a spread CD, where you take the 30yr Treasury yield, subtract the 2 year Treasury yield, and multiply by a factor (usually 4 or 4.5).
Sure, they are sometimes more complex than a simple flat rate, but the equations aren't crazy complex, and at the time, it was a great way for someone in their 80s to enjoy a very generous average portfolio yield of something like 6% while equities and all other yields were dropping. If she had stuck with bank CDs, the overall yield would have been maybe 2% back in 2009-2011 (and I shudder when I think of what her portfolio would have been over the past year or two as many CDs would undoubtedly have been called).