Good points being made here. I've mentioned my past (ad nauseam) sufficiently that my perspective is probably understood here. My comments;
-The Army normally expects that 90 to a maximum of 120 days of training (DOT)will be given to bring average Res soldiers to DLOC="Deployment Level of Capability" which is required IOT achieve the OPRED that Sandbag referred to. Note that I said "normally". Unfortunately, it is becoming increasingly fuzzy (IMHO) just what "normally" means any more. The Army is still under manning pressures, there is a much greater desire and willingness to use Res soldiers, and indeed we now have a pretty respectable pool of Res soldiers with at least one if not multiple missions under their belts. In the case of our Bde, 38 CBG, we launched a D&S Pl out the door with about 30 DOT for the current Roto of ATHENA. The Pl was all Res, although a few of the NCOs incl the Pl WO were ex-Regular Army. There were problems during training, primarily to do with fitness and weapons skills, but overall the trg (we ran it ourselves in the Bde) went well. The Pl did a good job overall-it encountered some problems (partly as a result of a lack of time to build cohesion, partly from other issues that were beyond its control and I won't go into here...), but all things considered I do not think its performance was measurably worse than an equivalent RegF pl;
-I have been a Res soldier on ops with the RegF, and I have had Res soldiers under my command on ops in a Reg unit. Most of the comments made by folks here are pretty accurate. If the Res soldier is physically fit, keen, understands that like any "new guy" anywhere he may have to prove himself, and is ready to work the "long haul" as opposed to the 48hour weekend adrenalin burst, then IMHO they will do very well. I found that once my coy deployed into theatre, after a while I had to look closely to see if a soldier was Res or Reg-you just couldn't tell;
-here on ATHENA 02 there are Res in the D&S Pl, in CIMIC, and scattered around all over the contingent. For the most part, they seem to work out OK. To me the question is not "this job for Regs, that job for Res" but "right soldier to right job". By force of circumstances, Regs will take some jobs to a greater proportion: this is normally based on trg and experience rather than prejudice (although we would be foolish to think there is not some of that still...);
-formed Res subunits were deployed in Bosnia on the later Rotos, and performed at least acceptably up to well. Again, it depends on many factors. Our Bde fielded one CRIC and contributed to another, back to back, and found significant differences in the way the gaining RegF units received, treated and employed these Res elements;
-I can relate from a non-military experience that there is always tension in any organization composed of "full-timers" and "part timers". I served for a while as a volunteer firefighter in a department that was manned by paid crews during the daylight weekday hours, then by us VFFs at night and on weekends/hols. The stations, trucks and equipment belonged to the VFFs-the paid men were put in by the local municipal government to ensure timely response during working hours when most VFFs had commuted to work. If a call came in during the "volunteer hours" then the VFFs fought the same fires, did the same auto extrications and medic assists as the paid men did during the day, but for no pay. The relationship was, to put it mildly, poisonous. It resembled the worst RSS/Class A relationship you could possibly imagine. So, I think that to a certain extent we may not ever be able to extinguish mutual suspicion and dislike that may be endemic to "mixed" organizations, although in my experience we have come a very long way; and
-in my experience Res soldiers are not, as a rule, given "back seat" jobs. However, as a commander I could see a particular ethical or perhaps moral issue that might appear to work against the op employment of Res in some situations. That is, IMHO, that no commander should willingly employ soldiers when he knows that their lack of skills or experience unduly endangers them or the mission. In some circumstances this might prevent some Res from being employed. But, if you apply that criterion honestly, you must then examine each soldier's true abilities, both Reg and Res. I daresay that I have seen a few people in the RegF who should not be sent on certain missions either. "Waddling sacks of sh*t" are not confined to the Res, believe me......
Cheers.