Out of the three you listed, my picks in this order:
1. Nitecore MH20 (NW version available)
I like the form and features, shorter lenght than S1, high output, quick acess to turbo, good throw (the slightly larger head and SMO reflector contribute), side switch with blue light battery power indicator.
Plus it’s an $80 light. So if you can get it for $50 then :party:
2. Astrolux S1
I have the BLF A6 and the S1 is a slightly upgraded version, high output on turbo, great neutral tint (3D), an excellent deal right now for $29 with the shorty tube included. (if you’re concerned about orders from BG China warehouse, always select Priority Direct Mail for the extra buck or two, your orders will arrive in 15-20 days)
3. Manker T01
Nice looking light and great output and throw for its size, but…14500 is low capacity vs 18650
AND first batch production run might have some issues, see this thread (starting at post #29):
https://budgetlightforum.com/t/-/36274#comment-859550
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If you can up your budget another $15 I’d get this:
http://www.eagletac.com/html/dx30lc2/index.html
Choice of LED:
◦CREE XP-L HI V3 Cool White
or
◦CREE XP-L HI V2 Neutral White
1160 Lumens (904 ANSI)
284 yards beam distance
Instant access to high, fast access to low
Rear switch (on/off) AND side switch (modes)
Blue LED battery power indicator under the side switch
10 year warranty
18650 powered, plus it can also run on a pair of CR123A batteries if needed.
Very comparable to the P12GT for less dough, plus a more compact size (shorter & thinner)
Here’s where you can order one $15 over your budget (Sale price)
(pre-order for NW tint)
http://www.illuminationgear.com/EagleTac-DX30LC2-CLICKY-ETDX30LC2.htm