I'm almost ready

Okay, I'm almost ready to do my first brew (extract). I'm thinking of starting with an English Bitter. I'm looking specifically at Northern Brewer's Extra Special Bitter. I LOVE NewCastle Brown ale, so I'd consider a knock-off if anyone knows of a good extract version.

But here's my real question. Do the finished results of an extract brew suffer from doing partial boils as opposed to full batch boils? My neighbor was telling me that the higher the specific gravity of my boiled wort, the less efficient the extraction of bitterness is from my hops. Is it worth "worrying" about?

Anyway, I'm grateful for this site and the helpful people here!

Most kits are designed for partial boils; they take hop extraction into account. That being said, your beer will improve considerably when you move to full boils. You need a couple more pieces of equipment to do full boils, so a partial is a great way to start.

Here is a link to AHS's clone of New Castle. I haven't made it, but they're known for their excellent clone recipes

Yes, hop extraction is affected by wort gravity and by bitterness concentration. So what that means is if you use a recipe for a full boil and do a partial boil the bitterness will be considerably reduced. It also means that it is going to be really hard to get a good IPA bitterness with a partial boil. However you can do better by adding much of your extract late in the boil instead at the start. This reduces the gravity of your boil for most of the time. Brewing software take the wort gravity into effect when calculating IBUs so you can adjust your recipe based on your equipment. Also most extract kits assume a partial boil and add more hops to compensate.
Craig

and thus, the larger the partial boil, the better.
before I moved to all grain brewing, and using a big-ass propane burner outdoors, I was limited to using two 12quart stock pots on my electric stove, and splitting my ingredients between them.
I still needed a gallon of top off water, but at least I wasn't really fighting the hop utilization.
but I wasn't making high gravity stouts or barleywine either

You want to brew a Nut Brown Ale if you want something that may resemble Newcastle.

Midwest has a clone kit of New Castle called Oldcastle Brown Ale. My buddy (uniconfis on this site) has made it before and it is nearly identical. Really good extract beer.

Thanks for the input everyone. I still need to do a partial, since I'm doing it on my stove, but I'll go as big as possible! And thanks for the NewCastle suggestions!!

edit for clarification: Doing a partial because of my stove's difficult time bringing anything to a boil, let alone 5 gallons of liquid!