Garmin 705 or SRM PCVI?

I am about to order a new SRM and I am completely torn on which to get. I live in San Diego, and run with a 305 and have no issues with the gps dropping out. From what I have read there have been issues with the 705 being all over the place with wattage or dropping the signal. Has this been corrected with firmware? I am looking to mount either computer on my stem, have people had problems with the signal when mounted there?

My PCV was rock solid, but gps is cool, not cool if it doesn’t work right.