Hi I'm a vers/bottom guy and I love to bottom!! I've gone into more detail below in hopes of explaining some feelings that I had. But to answer quickly before we get into detail, no the orgasms don't feel the same though they can accompany each other sometimes, multiple orgasms(remember no ejaculation during multiple orgasms) are very possible and they rock, and for me I love the experience whether I've cum or not... if he's fucked me good, I'm good. Here's some reasons why I like bottoming:
~I am not a sub but I like when someone else takes control and while you are most certainly in control of your own body when bottoming, because in order for you to enjoy bottoming you have to allow the top into your hole... he technically shouldn't be forcing his way... unless you're into that. (If penetration is painful, try putting your finger in your hole. But don't push your finger in, just rest it on the hole. Tighten your hole and then relax it and when you relax it, think about your hole opening up and taking the finger inside of it. Think thought process is amazing for beginners and for taking big dicks). But to just give yourself to another guy is an amazing physical and mental experience.
~When you get past the initial discomforts of putting it in the first time... a little pain sometimes(if he's super thick like my fb), just getting used to the feeling, adjusting the position you thought your quads could handle but can't, realizing there definitely needs to be more lube, etc. Once you get past all the business and take a second to realize that this man's pulsing cock is inside of your body and it feels good(full, stretched, warm), you take a deep breath and feel this release from your muscles and mind. You can feel his cock sliding in and out, it feels warm and there's good pressure. The feeling is more of a full body pleasure though. Kind of like the warming feeling that red wine gives you... it feels like a head rush. My chest gets hot, and its like there's these energy waves radiating from my lower abdomen.
~ The orgasm itself, in my experience, is amazing if the bottom guy is really turned on and horny/in the throws of passion. I've cum plenty of times while being fucked and jacking my dick... and it was kind of blah. Very much a quick hook up centered on the top getting off. But I have had amazing anal/prostate orgasms before where both people were able to find pleasure in the giving and receiving of pleasure with a partner. I think to enjoy bottoming you have to get into the mindset of wanting to take your partner into your most vulnerable area to give him pleasure while he gives you pleasure. Once I got out of the mindset that my pleasure is just a welcome after thought to the tops desires or that my pleasure is dictated by what my top does... the feelings I get from my ass and sex in general has become incredibly amazing!
Example: My ex and I had a very sex oriented day, we had anal sex 3 different times that day and I hadn't cum yet, and I was perfectly content with that because he had made me feel amazing... he had a 9-inch perfect dick and knew how to use it other than the fact that he was pretty quick to cum, but he was sit a hot fuck! Well this last time before bed, I was riding him and he was hitting everything and really into pleasing me and making sure I was getting off, and I was horned up from the entire day and his actions. The orgasm came and it felt like it lasted 5 minutes. Like take the head rush of poppers and increase it 10 times, and I could feel the heat of my body just intensify, my breath was taken away, eyes went blurry, I was moaning so loud, and every touch of a hand or move of his cock inside me just kept the pleasure going and going until I was finally able to come down. I was so light headed that my ex had to catch me and hold me so that i didn't fall off the bed! All the while, my dick had been soft and no cum... pre cum, but no ejaculation. Of course I came after a break and some fingering, but definitely not the same experience as a penile orgasm and ejaculation.
Also randomly, ejaculating with a guy inside me is hot and I love to shoot all over him and myself. But I find that if the guy is really big and thick that I can't really ejaculate with him inside me or its a really small load... and I usually shoot 5 or 6 streams of cum up to my face or pillow if I'm jacking off... So anal and prostate orgasms fill that void if I'm with someone with a big, especially thick, cock.
Hope that answered some questions, sorry I'm long winded!