I like the fact that after a refit phase you are never quite sure of the composition of the enemy force, and the fact that you can spend up on ? counters to confuse him. One of my peeves with ASL scenarios is that you always know exactly how many MGs/leaders/squads and what type the other side possesses.
It really depends upon the type of CG being played (e.g. day long CG scenario periods, as opposed to shorter time periods). The likes are pretty much the same for all as the RePh usually offers the chance to redeploy forces, either majorly or in a limited fashion; Offers a degree of FOW about reinforcements to be employed in the next CG period (i.e. scenario); the possibility of going "Idle" or giving the initiative to your opponent even if only in a limited fashion; and the ability to "out-guess" your opponent on operational employment of your forces for the next "active" CG period. Dislikes may be the almost total lack of any attrition of forces during an "Idle" period (very improbable in actuality, even during periods of relative inactivity in a given sector); Major Terrain alterations such as Flame/Blaze spread to mention just one aspect (results in several House Rules to address this when longer CG time periods are in effect); Relative stability of the Front Line of Troops (FLOT) during an Idle period(s), when in actuality it was usual fashion in most instances to pull back slightly to relieve direct confrontation in most instances (the longer the period of idleness, the more pronounced the distance between antagonists usually became).
There may be more of of each, but these are the ones that come rapidly to mind.
I enjoy the battle hardening the most. It gives you a connection to your units.
Also the ability to purchase ? and fortifications or special RG to accommodate whatever dastardly plan you have cooked up.
CGs are the ultimate ASL experience IMO, and varied options during the refit phase are essential to enhancing the immersion.
Managing your troop quality via the attack/idle choices along with elite RG purchases keep you making tough choices at times.
The only dislikes I have would be too limited options for RG purchase.
Some CGs represent a limited battle either in terms of time or available reinforcements or both.
It's more fun to have options and time to develop a strategy.
The smaller CGs can be plenty of fun, but Red Barricades is still the gold standard for many very good reasons.
It's not often a product just gets it SO right, but RB is definitely one of these.
I rather prefer the Platoon Leader ideas for unit re-positioning - base it on the intensity level of the fighting, rather than a simple "take it all off and put it wherever" or " only move it a little bit and that's it" routines that are the most common.
Of all of them, the best I've seen is Morin's VotG ones on RG entry for the Russians being dependent on map position of the Germans in relation to the Volga River.
The worst I've seen is the ability to create via RG a "flak tower" of Brit and Greek HMG's / MMGs / LMGs that wipe out all paratroops coming down on turn 1 in Cemetery Hill from the Church on the hill. That one needs fixed - may be historical, but it needs an "ammunition shortage" SSR to make it completely historical and fix it.
Dislike the mark and sweep Refits unless the CG date/times are clearly hours apart (AM/PM).
Like the setup areas that are the joining of areas X hexes from strategic locations over the RB-style perimeter drawing.
Dislike if the CG allows one to buy everything eventually. More hard choices for the RePh, please.
Dislike hard fortification purchases beyond CG scenario 1. Concrete pillboxes poured on the front in a half-day seems to stretch credulity. Rewards reactive tactics over strategic thinking.
Like the ELR/BH morphing of forces over time.