+1 vote for DIY. Some "techs" don't even have test equipment....they just tune until it sounds good through their talkback speakers
Let me be very serious for a minute though - I've had radios from Bells, GI Joes, Doc, Rogerbird, and more so I can tell you my experience.
If your radio has a problem - sure, send it to tech to fix it. If your radio is brand new out of the box (or was previously tuned or aligned if you bought used) then don't send it to anyone unless it isn't performing the way you would like.
An alignment is a pretty simple process and you're paying to ship a radio there and back (which has gotten pretty pricey lately as I can tell from shipping stuff for ebay) - then you're paying a tech for their time which can cost you $50 or more + tax. Again - unless your radio is out of alignment there is no need to assume you need to send it to anyone. In many cases most CB operators wouldn't even know if their radio was slightly out of alignment unless they have a locked clarifier and they aren't transmitting on frequency.
You can pretty much align most radio with a multimeter and a basic frequency counter and the instructions are simple - place probe on test point A and then do this and measure for voltage or measure for frequency etc. etc.
As far as a peak and tune - you have no idea what you are going to get when you send your radio to a tech. If you say I want it to be at 100% modulation than hopefully they can do that - but power settings and everything beyond that is a total crapshoot. Each one of those techs will set it up differently unless you tell them the exact output numbers or deadkey you want. And if you already know all that you can probably set it up yourself.
The risk of the "whackpack" is possible with many techs - and the other risk is paying $90 for a peak and tune and the tech just adjusts your power output slightly and turns the mod pot. There isn't a standard for any of it.
As far as taking advice - every single operator has a difference preference which you can tell from reading the threads - some like their radio to be loud and proud, others want it to be just right a 100% mod so you have to be careful who you listen to.
When I was first getting into radios - I sent one of mine to a guy who was known as "the specialist" for that type of radio. This guy had more people saying how good their radios sounded from him and how great he was, etc. etc.
When I got my radio back from him the deadkey was set too high - not just a watt too high but wayyy to high as in I would never run that radio with that high of a deadkey and even a newbie like me knew enough that it shouldn't be that high. I didn't have much experience back then so I can't speak to the "alignment" but I can bet it wasn't much better than the tune.
I can say that I've sent a warranty radios to Ranger/RCI and they fixed the problem, and I've sent a Magnum warranty radio to the radio shop in Ontario California with a complicated issue and they fixed that but beyond a factory warranty repair i would just save your money and figure out how to DIY, the people on the forum can walk you through it and then you can do it for every radio you own.
teach a man to fish...