Strengths: The information you can get on the fly from the 305 is phenomenal and covers bike and run equally well. The watch is comfy despite it's apparent size, even on skinny wrists. Backlight works well in winter. Virtual partner, HRM, accuracy on distance, lap alerts (with time/dist) are just some of the things I now would not be without if I was to replace the 305. The navigation between screens is reasonably intuitive as is setting up the information you want on the main navigation screens, the buttons easy to use (even in the dark) and the paint hasn't fallen off the buttons unlike my (cheaper) sportswatch. I even like the fact you can have a bigger display setting which is handy if, like me, your eyesight is a bit dodgy!!
Weaknesses: The watch is slow to acquire and easily loses signal in the trees and under bridges which is a distraction. The PC software is absolutely shocking - although there are good alternatives on the web (Sportstracks for example). The single biggest weakness of the unit is that it is not waterproof unlike many of the natural competitors - this prevents it from being the triathletes tackle of choice and limits it to running and training only which is a real shame. The hard chest strap is not as comfy as the soft polar straps and can chaff on longer runs.
Overall: Although very fond of my 305, I am always on the lookout for a replacement which indicates that it has some weakness. There are bugs in the software on the watch which make it occasionally lock up and the lack of waterproofing is a huge drawback for me, on the other hand, the many excellent features and the quality and range of the data available are fantastic and will be hard to beat for the price. This certainly ticks 9/10 of the boxes for a good priced, good value S&D monitor + HRM.
'REASONABLE HRM, POOR DOCUMENTATION, GENERALLY EASY TO USE'
Strengths: Ease of use, logical menus, clear display.
Weaknesses: The complexity of the 3 running programmes is a challange for a newcomer to HRMs, similarly I am not convinced that the zones are accurate. The lower zone barely requires any physical acitivity before I'm out of zone. Thanks to the forum I've already (falsely raised my Min HR by 12 beats) - now petrified that I could over exert! Could also do with a stopwatch feature. Lastly the strap is truely aweful!!
Overall: I've only had mine 2 weeks and already feel familiar with it - I think that if I was to start serious training or x training it would be limited. Apart from the -ve comments I am happy with the watch and glad that I invested in one... as my son said last weekend "Dad is still beeping so he must be alive"!!!!!!!!!!!