How were the SS viewed by the regular German military? Respect, disdain, etc?

I assume you are speaking of the armed wing of the SS, the Waffen SS here?

The picture is not as clear-cut as one might imagine.

The Heer, the German army, had a long and proud tradition of being one of the best armies of the world, had been dominated by aristocratic officers, but was still very meriocratic, with very tough demands to become an officer, especially a staff officer. Connections could only get you into cadet school, it could not make you pass it. During the years preceding ww1, during the war after immediately after, middle class men started making inroads into becoming officers. Erwin Rommel was one of them.

The Heer and the nazi party had a complex relationship. The Heer wanted a strong Germany free of the Versailles restrictions on the army, and feared a socialist or communist takeover. The nazi party became the best bet for them, and they took it. However, generally the aristocratic officers had nothing but contempt and disdain for the armed wing of the nazi party, the SA. When Röhm, the leader of the SA, wanted to build the new German army around the SA rather than around the old Heer, the officers had enough. At this time, the nazis had not fully taken over the state as they later would, and Hitler needed the support of the army and the industrial elite (and though them most of the conservatives) and obliged - Röhm was killed in the night of the long knives and the Heer expanded on its own terms.

That said, the nazis did try to control the army, but generally failed. Expanding the SS to create their own army became a solution to the problem of the Heer being 'decandent', 'soft' and not 'hard enough' for nazi plans. Now, the Heer commited plenty of war crimes and atrocities, especially on the Eastern Front, but the worst offences were commited by rear area Einsatzgruppen under SS control.

When the SS started forming field units in 1939, the Heer was not keen on the idea. The SS had to accept ex-Czechoslovak MGs, rifles, artillery and had to use Mauser Schnellfeuer automatic pistols instead of SMGs. They also had an idea that zeal and morale was more important than tactical skill and flexibility. During the Polish campaign, these SS units performed well under Heer standards, with the SS Germania regiment fleeing, abandoning all heavy arms during the counter-attack by a Polish regiment. The SS Liebstandarte regiment had to be rescued by Heer units after being surrounded by Polish forces.

During this time, the Heer generally had nothing but disdain for the Waffen SS.

After the Polish campaign, the SS hired some ex-army drill instructors, looked over their tactics and doctrine and managed to acquire better arms for their troops. During the campaign in the west, the SS-VT division performed decently, but not more than that, against the unprepared Dutch they faced, while the motorised formations did perform on par with the Heer, but got known for commiting war crimes.

After the western campaign, the SS splits into two forces - the motorised forces, centered around the Fürher, Das Reich, Liebstandarte Adolf Hitler, Germany and Deutschland regiments created an elite that was on par or at times even better than the best partsof the Heer. Generally, these formations were respected for their ability in battle by the Heer. However, the SS also raised multiple mediocre and downright crappy formations. The SS Polizei division and the SS Nordland division are examples of decent divisions, while the SS Nord, SS Charlemagne, SS Skanderbeg, SS Hanschar were very bad formations.

The bad formations were often rear area units, fighting partisans and being guilty of war crimes and brutality, and often faced disdain from the Heer.

By 1943, the vast majority of the SS were crap formations.