This post should actually be titled, "Wearing Bogu for the First, Second, and Third Times". I practiced in bogu for the first time two months ago, but the busy-ness that kept me from practicing also kept me from writing.
My first impression was that even borrowed bogu isn't as uncomfortable as I was led to believe by reading about it online. Though don't get me wrong, it is still uncomfortable! And hot. I'm secretly a little glad that I was too busy to practice during the hottest months of the year.
I was also surprised that I didn't notice the bars on the men (helmet) at all! I assumed they would bother me, but they don't.
Now for the bad:
Until I wore bogu, I didn't realize just how much I rely on the tactile feedback of feeling the weight of my hand against my hip, etc. to gauge whether I am in the correct stance. I can't feel any of that wearing bogu, and even worse, I can't look and see whether I'm in the correct stance because the men severely limits my range of vision. Add to that the fact that you move a little differently wearing bogu than not and everything happens much faster because you're less likely to be hurt or hurt others. I can tell I'm not moving/standing correctly at all. I feel like I need to relearn all the basics all over again in bogu.
The second really difficult thing is just that I can't understand Japanese as well when I (and the people I practice with) are wearing bogu. The men muffles sound a little because it covers my ears. And when others are wearing men, I can't see their lips and facial expressions as well, and when they're wearing kote (gauntlets), they don't gesture as much.
Wearing bogu definitely requires some adjustment. I haven't gotten frustrated yet, but I until I become comfortable with it, practice won't be as fun as it used to be. :/
 most of my order from Chiba Budogu didn't arrive until last week and I'm still waiting to for my sune-ate (shin protectors) to arrive.
 to accommodate the bulk of it -- for example, my do (breastplate) makes my waist significantly larger!