My sleeping bag collection used to be just two - a 2 pound +25F REI Halo and a 4+ pound -30F Mountain Hardwear Wraith. The MHW bag was an ebay snipe and is fantastic, warm, big, waterproof on top, but it packs very large and is heavy, and in the Sierra it is usually too warm unless it is the coldest part of the winter. My REI isn't warm enough for September in the Sierra, not every night, but higher up on Whitney I was cold in it last time I used that bag in fall.
So last year I finally bought a zero degree bag to fill the gap between the two bags: a Marmot Couloir, half off on Steep an Cheap made up my mind and it is a great bag - plenty warm this April and definitely the bag I'd take in September/October as well. 3 pounds, packs well, and already shows the battle marks with a hole my ice axe ripped into the hood when packing it away
For a long time I was hoping to find a Western Mountaineering bag in this class, but those trade like aged fine wine in the used market, while sales on new WM bags are rare. Sleeping bags do last a long time if you take care of them, so spending a little more isn't a bad idea if you keep using the bag frequently over the next decade or more. Or buy one on ebay, use it, sell it again.
Sleeping pad - I love my Exped Downmat 7 UL in the colder seasons, while in the summer I prefer the simple RidgeRest foam pad. I've had 3 inflatable pads before the Exped, and eventually all of them developed slow leaks, so I keep going back to those uncomfortable foam pads when on longer trips. but in terms of comfort there is absolutely no comparison between the two. I sleep a lot better on the Exped.
