In regards to logi it really comes down to your comfort level and what works best. I started off as an MD logi, but recently I switched to a LR Logi and now I run AR (which to me is the best of the 3 for a logibro, but that is just my opinion. MD comes in a close second, with LR last). I've been both a full support logi as well as a combat logi, and from what I've seen it just takes time to determine what you are best at. What makes the logi so amazing is its versatility, you can play it so many different ways and evolve based on the current combat situation.

Going back to the topic of weapons, I would suggest trying out all of them, as each weapon has some negatives when put on a logi. As you pointed out, the logi doesn't have a sidearm, as such running a LR logi becomes somewhat tricky especially when dealing with CQC. However, the LR is a great crowd control weapon (as well as a killing machine) as you can force the opponent into a corner, allowing you to not only get to your injured teammates but also allow the rest of the squad/team push forward.

The MD is very similar in that you can create cover (the MD shells produce smoke. Tip: use the EC-3 or boundless as the increased blast radius creates more smoke) as well as help take out injured enemies. However, the slow rate of fire, small amount of ammo and the potential to kill yourself makes the MD a tricky weapon (further, when dealing with CQC, you need to account for the change in arc as well as the movement of your opponent; Also, if you use the MD, don't be a scrub and spam shells at your enemy without thought or accuracy, spend sometime to figure out how the arcs work and push yourself to achieve a direct hit on as many shots as possible).

The AR seems to be the most balanced weapon, especially where sharpshooter allows you to stay at a distance, pick off your opponents and allow you to get to your injured teammates. For me, it's fast becoming my favorite weapon as it's great for long distance shooting as well as CQC. In fact, thus far I've not really found any major negatives, unless you account for the "smallish" clip size. It just takes some practice to get used to, especially if you are coming from a different weapon.

As for the other weapons, well I've yet to try them (I wonder if a Shotty Logi or a Sniper Logi would work?)

To sum up my post/TLDR: spend time experimenting with the Logi, figure out your favorite play-style as well as the type of weapon you will be using. Also have fun with it!!

Osiris.