I don't know about you guys in so cal....but I never had any problems with mine when I owned my teg.
I guess getting the bypass valve would be a good investment and it'll give you peace of mind.
As far as installing it...it should take you about 30 min or so....not too hard. Do yourself a favor though if you get the bypass valve....MEASURE and MARK before cutting....hehehe
__________________
Jimmy
Team B.O.B.™ - Ballaz on a Budget
R.I.P Huan Vo 11-19-2008