Hmmm why do I get the feeling you guy's are looking at camera's based on specifications and numbers alone? If thats how you intend to purchase a camera, you will almost certainly not get a great camera.
Think of this way - more megapixels "doesnt" mean better quality. In fact, given the size of the sensors being less then 1 inch in most sub £250 camera's, the higher megapixel count will actually be a hinderance and mean worse quality rather then higher quality.
The higer the zoom doesnt mean the better the image, as in the case of the Z612 vs the Z710 - the Z612 is an obsolete product, recently replaced by the Z712 and whilst a model like the Z710 may have 2x less optical zoom, it has a newer CCD, and features newer colour re-production and image processing algorythm's, which in turn lead to a far better quality shot.
Also, my camera has only a 10.7x optical zoom, which may sound crap compared to some. But not only does it have a lens of similar quality to high end SLR lenses, but it also has the ability to accept additional lens extensions... a 3x lens extension, and I then have the possibility of upto in excess of 30x optical telephoto end. The same with a wider angle lens extension would give me the possibility of maybe a 16mm wide angle end instead of the rather impressixe 28mm it has as standard.
Dont buy a camera based on megapixel count or how many mm the optical zoom is, buy it based on image quality, do some proper research, also buy one that you need, not that looks biggest and best. Without a real purpose for having such a high zoom, why buy an 18x for instance? Why buy a 12 megapixel camera for instance, when a 4 megapixel will perform just as great, if not actually better due to the size of the sensor... are you really intended to do prints bigger then A3??
For low light ability, you really need to get a camera with as high an ISO as possible. Take the Z612 for instance, the top ISO of 800 is only available when shooting in 1.1 megapixel mode, so its native top ISO is actually only 400, and to find the highest decent quality ISO with which image noise doesnt start to affect the shot badly, you go back a step further, which means the ISO would be a lacklustre 200.
My camera for instance shoots at upto 3200 native, at 800 and 1600 the quality is totally fine for using in say a print or a high quality web image. 3200 isnt too bad itself, but the noise does become noticable. Dont always go instantly on the ISO rating though, again, you need to find out how the camera actually performs at higher ISO's... another camera with an ISO of 3200 may perform really terribly bad at anything above say 800, its all to do with how badly the noise and luminance affects the final shot.
Id say first of all you need to decide what you need the camera for... if it just shots of the family, the odd shot of the car to put on the web etc, dont bother spending masses of money on something which has all the specs that you will never need. Its a case of why spend £230 on a camera that for your requirements, a £90 camera would be more then adequate?
If you want to go a step further and maybe become an amateur photographer, then a bridge camera is the way to go for both optimum quality and flexibility at a decent price. Landscape and scenic photograph demand high zoom levels, bridge camera's provide this as standard, and usually have the flexibility to go further, but this depends on the model you buy so check it out first. Then again, dependent upon the type of photography you do, a 0.4" macro mode would be better then a 100x optical zoom, again, most bridge camera's can achieve this or very near it as standard.
My current camera kit is the Fuji Finepix S6500FD
, along with a 2GB XD card (you really do need a 1GB minimum), a monopod and some 2500mAh batteries, a 1 hour charger and an in car adapter. This is the basic kit required to get the best use out of this camera at stock, I still havent found the "need" for any higher telephoto of wider angle lens extensions as yet, even though I consider myself an amateur landscape and scenic photographer.
This camera isnt perfect in every sense of the word, it features the unique Fujifilm SuperCCD 6th generation sensor, for those who dont know, the Fuji SuperCCD is hexagonal pixels instead of round, so provide more calirty and definition. It also has a 10.7x optical zoom with the ability to use extension lenses, it is 6.3 megapixel, has a maximum ISO of 3200, can macro to less then 1cm, has an EVF and high quality bright LCD, features manual focus and manual zoom rings (believe me, once you have tried manual zoom, you will never go back to electronic zoom) and uses the same lens as the S9600. Oh it also has silly features like Face Detection, which some people may be interested in.
It has a wide range of modes, including the dreaded full manual mode, which ensures the user has the same amount of control over the shot as they would have on an SLR.
It took me many hours of searching around the net to decide upon this camera. I was convinced for many months that I was going to buy the Kodak Z710, which seemed to be amazing from the specs... but as I read more and more reviews of it, the general feeling was quite negative, and the S6500 and its big brother the S9600, and its younger brother the S5600 had such positive reviews and won so many awards between then, for the price I was looking to pay and the type of photography I intended to use the camera for, I found the S6500 would be most likely to meet my needs... and it hasnt just met my needs and expectation's, in many ways it has exceeded them.
At the end of the day though, if all ye can see is numbers, buy the biggest zoom and highest number of megapixels you can, im sure the camera will more then meet your needs as you arnt a photographer so wont need anything special lol.