One the backhoe issue, I went with the 47. My reasons were based on how much I would actually use the hoe, and what the uses were. Honestly couldn't think of anything I would need to dig 8 ft. down for. Understood that the smaller hoe meant moving the tractor more. Neither one is cheap, but $1000 is $1000. I was already spending $29k, and I couldn't justify another grand for my use.
If the money didn't matter, I would have gone with the 48. For convenience sake (moving the tractor), and just because it's BIGGER. Looking at it now, I still couldn't justify the extra money for the 48, but have certainly made use of the 47. It's a very capable hoe. It was hard not to buy the biggest and best tool available; I usually do that. To my amazement, I have probably spent 1/4 of my seat time using the hoe. Other than cleaning up after the dogs, I haven't picked up a shovel since I bought it. /forums/images/graemlins/smile.gif
Sometimes I wonder if the 48 makes a big enough difference over the 47 for someone, maybe they should have a bigger machine all together. That is somewhat assuming they are pushing the limits regularily.
Your decision should boil down to your needs. If you plan on using the hoe quite a bit, going larger would probably be good. If you can live with the 47, go buy some more attachments.