I have had and used  Raymarine 600W and 1 kW traditional, Furuno 600W and 1KW traditional and now Garmin 600W traditional, 600W chirp and 1 kW chirp.

My experience is:

- transducer location more important than any other factor  

- Furuno a bit better than Raymarine

- Traditional tone sounders give a better indication and understanding of bottom hardness than Chirp. Furuno definately the winner

- Traditional gives much better tails which is useful for the above  

- chirp needs clean water over transducer, very sensitive to aeration. I would generally not recommend transom mount for chirp

- Chirp gives much better detail of fish close to the bottom   

- Chirp better distinguishing between small and larger fish  close to each other

- Chirp has much better depth penetration. 600W chirp gets deeper than 1 KW traditional tone, 1 Kw chirp gets deeper than 2 kW traditional. 

I now run only CHIRP and now fish almost exclusively fish shows. But I do miss the Furuno traditional bottom image to show hardness and tails and would consider adding a Furino back just for this, but 1KW Chirp is my go to  

 Hi Curndog I bought a garman sv95 chirp recently. I bought it to replace my old navman plotter and add some extra features to my furuno 585. Got to say realy good unit and has already put me on some good fish.

Id definatly go the chirp unit for a few reasons, it will run to my knollage chirp for down and side scan so depending on transducer you can get deeper readings on chirp units, supposedly better target seperation. I carnt say for sure as havnt used the non chirp version or botherd running fixed frequency but im pritty happy with what it shows.The chirp unit can also run at fixed frequency so you can customise frequencys for different transducer cone angels or play with what frequencys are working best where your fishing. If you dont like the chirp you can just set it to 200khz or what ever suits (depending on transducer).

The feed back I got from garman allso is the chirp running on these is the same full band width chirp as the higher end gpsmaps xsv series just only capable of 500w making it pritty good value. Note that gpsmaps xsv series is only offered in chirp and chirp was an upgrade for the unit you're looking at. Looked like a easy choice for me and I dont know that you would save much going non chirp either hope ive helped a bit anymore questions happy to help.

 Id just add to Johns coment re chirp transum mount transducers. Both sounder on my boat are transum mount same location but opposite sides of hull. The furuno will read at higher speeds which now makes a bit of sence but I still get a good 15knts out of the garman chirp on an average day before it breaks up.

 Thanks a lot for your advice guys. I have used fury no most my life and also like the fact you can read the bottom hardness. I think i will go the chirp and learn how to use it. Planning on buying from bcf (hopefully they have a Boxing Day sale). Bristolio - did you just get the stock transducer that came with the unit or did you upgrade? I only really fish in max 40m so I'm thinking the stocky should be fine. Cheers

 Hi I just got the standard transducer think gt52hw from memory, apparently made for fresh water but I found it pritty good for were Ive used it in salt. I bought it just befor the ban so ive only used it a couple of times and they were inside of 25m because I was interested in playing round with the scaning. I recon the traditional sounder would easerly read 40m but dont know how deep the scaning would. Theres a few reveiws around for that transducer with screen shots ect. if u search around.

Theres a few more garman transducers that are supposed to give you more depth but id doubt youd need them gt51m from memory but at around $700 and up youd have to work out if it was worth it, havnt used it so carnt comment. Garman also make through hull transducers to suit. Airmar allso have compatable through hull transducers but I think you would end up loosing scaning as you can only run one transducer at a time. End of the day they come with one so carnt hert to try it just have a good look for anything down the hull that would cause air bubbles infront of where the transducer would be mounted lifting strakes ect. Im told they make a bit of spray to so may or may not need a spray shield my old boats got a pod so dosnt bother me. Good luck mate

 Thanks heaps mate you been a big help. Il go with the standard and go from there. Cheers

I have the GT51 (600W medium CHIRP) as well as a B265 (1kW high and low CHIRP).

Bang for buck the GT51 is bloody good. Reads down to 450m which is awesome for a 600W and still very good in shallow!