I am able to achieve great intense orgasms with aneros but have experimented with dildos with not as great of success. Then again I haven't invested as much time as I did learning aneros. Just wondering how the feelings differ and if its possible to learn both and switch between them depending on the mood? I would love to be able to orgasm from my girlfriend pegging me but the few times we tried it I wasn't feeling it. Was also wondering if there were any guides more directed toward dildo orgasms rather than aneros. I'm not sure exactly what to work towards when using a dildo.
Just wondering how the feelings differ and if its possible to learn both and switch between them depending on the mood?
It is possible to learn to orgasm from both Aneros use and dildo use. I think it is a matter of accepting the differences in stimulation/sensations and focusing upon those desired due to one's mood. Generally speaking Aneros use is much more passive and the physical sensations generated are more subtle than with dildo use. Typically, in situ, the average Aneros is approximately 1/2"(12.7mm) diam. (1.57" circumfrence) sitting in the anal canal whereas a typical dildo will be 1"(25.4mm) diam. (3.14" circumference) or greater. This amounts to a 100% increase in anal sphincter dilation, creating greater stretching tension and increased nerve stimulus. Aneros use differs significantly in the amount of movement through the anal canal, typically the Aneros moves very little (nearly 75% of the members report movement of less than 7/8"(22.22mm) while dildo play may involve typical movements of 4"(100mm) or much more. This increases stroke area anal contact from 1.37"² for Aneros massagers to 12.56"² or more for dildos, that's a nearly ten fold increase! Aneros massagers are designed to effectively engage the prostate on a continuous basis while most dildos only tangentially engage the prostate on an intermittent basis for each stroke used.
I would love to be able to orgasm from my girlfriend pegging me but the few times we tried it I wasn't feeling it.
This is a matter of rewiring/training here's a femdom approach but you could train yourself in a less formal manner on your own by basically having your partner do this at your request.
Was also wondering if there were any guides more directed toward dildo orgasms rather than aneros.
I'm pretty sure you could probably find some guides by surfing the internet, here's one you might find interesting -> Stimulating the Prostate to Orgasm (III): Dildos and Thrusting
Good Vibes to You ! 
I have had SOME success with my Ambit P-spot dildo. While thrusting can certainly feel good at times, my success has come from using the Ambit the same way I would my Aneros device. Lube (50%-100% more than I normally use), insert, and relax. I have had some intense O's with the Ambit, but it does not always want to perform. Sometimes I like something a little larger (1.5" diameter tops for me) and the Ambit fills the bill perfectly. I have used the Ambit for a couple hours, then switched to my Eupho and had some awesome results. The larger size really seems to wake things up down there and prime the pump for later on. You are correct that using a dildo is quite a bit different than using an Aneros device.
I used to fuck myself with a dildo, any dildo, for a long time most sessions after the Aneros didn't make me orgasm (the days before my first super O and dry Os were identifiable). I just felt like if it was more intense and more hardcore I'd "cum" from anal/prostate stimulation. Wrong. I never did.
But now I focus g-spot dildos directly on my prostate and further back on my seminal vesicles. I "dance" around these places with slow soft movements, sometimes vigorous intense movements, and side-to-side/rotational movements. Depends on how you hold it too. You can push the dildo down towards the floor (if you're on your back) and that angles the head directly up and at your prostate. This is more intense. Or, you can angle it straight and the g-spot angle part slips past your prostate, making contact but it's more soft and gentle. Or, you can turn the g-spot part upside down so it's 180 degrees opposite your prostate and try that. I find that to be pleasurable too!
My wife pegs me from time to time. Takes some prep work. I usually warm up with Aneros and sometimes a dildo or two for about 20-30 minutes before she enters me. This gets me ready for literally anything she wants to do. Pain is a non issue because my ass wants it more from being warmed up. If you want to get more out of pegging, you might want to start alone with your toys and get very worked up for it. Really try to eroticize your anus and prostate; really try to get your rectum very warmed up and prepared for some serious fucking.
It's the same for a woman in this regard: if she's wet and swollen, your penis is welcomed and she's ready for it and probably whatever your penis is able to do. If not warmed up and wet, it's not that great. Same for our asses. You can't just lube up and let her jam it in there. That's like starting a solo session with something bigger than the Progasm right off the rip.
Lastly I find when I'm facing away from her and she's trying doggy style on me, it's not that great. Unless you have a dildo she's wearing that can be rotated so the G/P-spot part of the dildo actually makes contact with your prostate. If it doesn't it can be passive and feel good, but if it's a decent sized dildo you might wind up feeling discomfort (I do). Another sure fired way to get it right for you is to get on top of her and ride her. You'll gain a new appreciation for all the work she puts in while riding you: when your legs start burning after a few minutes, look down at her and thank her for everything she does for you! But you can control speed and depth, and angle, very very well while on top.
Eventually you will both be so eroticized that you'll both be cumming your brains out as she's inside you. It's the orgasms you'll have when she's pounding your ass into oblivion and keeps on going throughout the entire orgasm you're having. When those Os come on, you'll be begging her to not stop like "PLEASE FOR THE LOVE OF GOD DON'T STOP!!!" and after that, everything pegging-related will be passe and part of your life.
Rumel,
The Femdom approach you posted I have talked about in earlier posts. I believe following it would indeed work in rewiring you. It will make your prostate very sensitive over a month or two to any stimulation and may be an approach men can use when other methods do not work. My prostate is pretty stubborn and I was considering using this method. I will let you know how it goes