Looking for first hand experience with any of these four models

Hi there. Been a lurker for a while, first time poster.

So I've been commuting on a bike in the Boston area for over five years now
and am looking at buying one of the following bikes. I'd like to hear from
anyone who has first hand experience with any of these models: likes and
dislikes.

I rode a mountain bike (an old specialized) with slicks for about four
years, and one day came across an old (think early 80s) road bike
(cannondale) that someone was getting rid of, and never road my mountain
bike again. Being that I very rarely change gears (it has to be a very steep
or something), I got to thinking about going to a single speed. Not fixed. I
like having the option to coast.

And I'm interested in the following models and what anyone has to say about
them. Of course in the end, I'll have to go ride them and see what fits, but
I'm still interested in any opinions here.

The bikes are the specialized langster (not comp model), the redline 9.2.5
model, and two bianchis: the san jose and the castro valley. I know this
last bike is not a single speed, but I'm somewhat interested in it as well.

Thanks for any thoughts.