the price of gps systems has come down massively this year... whats best?? hard to say. I've had garmin, lowrance, navman and magellan systems, and have all been very reliable. what ultimately makes the difference is the charts that you buy to use on them, but even the difference in these is not as great as it once was.
for boat anglers, many of the features of modern plotters never really get a look in, we just point em at where we want to go, and when we've done there, we point em somewhere else.
If you're budget runs to it, I'd say go for a colour one, I'd always had black and white plotters till this year and its much nicer/clearer in colour, but no more efficient.
I bought a cobra plotter earlier this year with the full UK and Ireland chart card, annd really like it. has some neat features the others don't have.
but you can now get black and white plotters upwards of £150 where you'd be paying 500 plus just a few years back