I also have been considering a new helmet because my helmet is 7 years old and came to the following conclusions:

The helmets I am most interested in are not available in the U.S. (MET and ABUS)
I was thinking that the foam in helmets degrades over time and that would be a reason to buy a new one - but it turns out not to be the case so the helmet I have is still good and I do not need to spend money on a new one.
There are no peer reviewed studies that prove MIPs is effective.
The studies that were done was with dummy heads, not real people.
There is no published data from actual accidents that shows that MIPs is effective.
I have no problem with people wanting a helmet with MIPs, but I have seen no proof that it makes a difference.
There are other factors that are probably more important than MIPs.