Nothing wrong with a Packa ... but this topic has been done so many times..
There are over 500 threads on Rain Jackets 4 pages on the same subject.
Bottom line is to find something light with pit zip and trap a layer of air for spring and fall to keep your core warm and dry. $100-$200 shells that are breathable tech is unnecessary. Under 8 oz if you can find it. Most of the time I use a 4oz disposable poncho from the $ store.