The basic differences between 406mhz EPIRBS these days are the manner in which they are activated, the inclusion or not of a GPS and quality of manufacture. While it is easy to advise anyone to go for the top of the range, this may not always be necessary. If you will be sailing offshore, it would be prudent to buy an EPIRB which releases automatically, activates automatically and contains a GPS. The GPS provides a measure of searchable accuracy previously unattainable and the less time you are in the water waiting for rescue, the less chance there is of you and your crew perishing from exhaustion, hypothermia or from drowning in big seas.
Automatic release is also important. Imagine the boat going down in front of you and knowing the EPIRB is still firmly strapped to the boat. Automatic activation becomes important if someone is disabled during the emergency or if seas are so big that immersed crew cannot find the EPIRB or cannot swim through liquid mountains to reach it anD flip the activate switch.
The amount of risk you take by going handheld and hand activated is something only you can assess. Inshore many people still have small 121.5mhz units. The bottom line for EPIRBS is similar to the decision to carry or not to carry a liferaft. Chances are you will never need to use either, but I imagine most offshore sailors (me included) have both a serviced liferaft and a fully featured EPIRB.
It is difficult to justify paying a lot of money for something which we are all 99.9% sure we will never need.....but in my case I just thought of how much I care about me and CB, and the decision became simple.
WARNING: PERSONAL INSIGHT FOLLOWS:
(PS. 'Gorbachev' when I'm in strife, 'Lady Samurai' when I am getting the 'glare', 'CB' (Cherry Blossom) when I have done a good thing....Praise every god in the cosmos
, she has been CB ever since she realised I was a lost cause and there was no benefit in trying to make me more responsible.)
(PPS. The now mature offspring still piddle themselves with laughter whenever I remind Mum that she will not be perfect until she can say 'Around the ragged rocks, the ragged rascal ran'.....Jappos...They can be so entertaining
Meanwhile she reminds me I'll never be perfect until....well..never really)