My first trip a few weeks ago was 1 tab of acid, 200 - 400 mg of methamphetamine and an indeterminable amount of weed.
The first half was very euphoric. Had fun socializing, made all sorts of cool connections with people, and omg the music felt amazing like nothing else. The closest I can come to describe it was like an explosion of orgasms rolling through your body, touched me really deeply too.
Around 3 hours into it I took a little more meth and that threw me over the edge. Heart started racing, which made me panicy, the fact that I felt like I had liquid running all over my body and couldn't shake the fear that I'd somehow spilt a drink over me or had gotten piss on my clothes in the bathoom even though I constantly checked that I was dry every few seconds. I mostly spent the next 3 hours wandering in a daze, completely whacked out of reality. It wasnt' a 'bad' trip, I managed to hold myself together throughout the second half, but (other than random moments throughout which were truly magical), the second half was definately not the same pleasant experience.
After about an hour or so into the trip I could barely communicate with people, whenever I thought/felt/saw/experienced something amazing I'd get the urge to go share it with a friend, but as soon as I found someone to talk to I found I could never find words to convey the magnitude of what I wanted to share, so I'd just mumble or stare or go 'hey uhm, wow, just wow.'
For about 6 hours afterwards my sense of reality was still distorted, I could talk, but it took a lot of effort to string words that made sense together. I eventually got some sort of sleep a good 14 hours or so after first dosing, and woke up feeling happy, though very scattered and disjointed.
Anyway yeah, I think the meth both enhanced and ruined the experience. For the 'euphoric' phase it really kicked me into a positive mood, gave me tons of energy, opened me up socially and made me feel really good. It was when I took too much and it started making my heart go crazy that it threw my trip off. Though even through all the paranoia and feeling totally lost and whacked out, I think the fact that I was still high on meth and feeling good is what prevented me from being thrown completely off the deep end.
Can't do a direct comparison because I've never tried acid by itself (hoping to remedy that in a few weeks), but I feel that as long as you keep the dose below anything that would cause issues for you personally, it would probably help enhance the experience.