I bought these two, intending to send one to my Granddaughter in the wilds of Southern California. She needed something brighter than the nice, but dim Inova X1 I had sent her off with. All are compact lights, very good for pocket, camera bag, or night stand.
The Sipik is a good light, worth what I paid for it, (Like, $6, iirc.) but one of the pocket clip screws’ hole was stripped out, 
so I put it back on with blue Loctite. That doesn’t work, I’ll just take it off! I also didn’t like the sliding “focusable”? head…it was always at the wrong setting, so I put an o-ring behind it, which keeps it at (for me) a proper head setting. But, it is bright, and has a fair run time, just right for a spare light, if one of the others goes out, or is not available. It will tailstand, sort of…the tailcap switch protrudes a little, but, not enough to make tailstanding difficult .
The Hugsby P31 is a very good light, 3 modes…High, Low, and strobe. I let it run on high for 20 minutes, and it got very warm, but not uncomfortable at all. Bright on High, and low is no slouch, even at backyard distances, and the strobe is fun. It Cost $13, worth the $$$. 
Both are much brighter in a side-to side comparison with my Inova X-1, and they are about the same length. Both are a little fatter than the X-1, but still very compact.
Sooo… what did I send my Granddaughter? A red MagLed 2 AA…I figured she could find it in her backpack easier than a smaller, black light, and It is BRIGHT!