Don't know much about the MS series but I'll weigh in a little. I have carried a Pentagonlight in my pocket for almost 2 years now so it may seem a little too obvious how much I enjoy them.
I hopped on the Pentagonlight bandwagon when they were first released because their X2 provided me with a weapon-light for 55$. Over the next few years I purchased quite a few of their lights and have had a couple of problems but no complaints with their products.
My problems were due to their incorrectly implemented circuitry when they first released their L2 3 Watt LED light. The issue was resolved quickly with both my lights and future production runs. In total I dealt with their customer service 3 times and each time was treated with respect and my issues were addressed as important. They are aware of CPF but as far as I know have no presence here.
Their product line is somewhat small and they seem to have scrapped their 12-volt turbohead monster (r.i.p. the X4
) but is reasonably varied (5mm cluster lights, mini-turbo head 9-volt lights) and they released a very non-mainstream design in the Molle LED light that seems to have been recieved very well. I am unsure of their position on CREE LEDs but they seem to be continually improving their line so CREE may not be far off.
When they were first released the threads were fairly rough and the lenses were plastic but within 6 months the lenses were replaced with mineral glass and the overall fit/finish were improved. They also seemed to have improved their reflector finish, making it much smoother, to aid in throw. Interestingly enough the current HA X2/X3 seems to be sporting a pocket clip now.
Overall their lights are slightly larger than comparitive lights of equal voltage, usually a little longer and heavier but not significantly so. Their lamp assemblies are well designed and lean heavily towards throw (except the 5 watt L3) and are typically on par with the Pelican M6 (a real thrower). Each light they produce is individually serial numbered. They also operate with the batteries positive end towards tailcap and will crush the batteries is they are inserted backwards and the cap tightened all the way. The barrels of their lights will not take 18500/18650 cells without modification.
Runtime for their lights seems on par with their estimates for their Xenon models and slightly overstated for their LED models (a custom maker did a test on the L2, search should find it). Output seems on par also, Xenon is spot-on and LED is overstated. Shock-isolation is excellent, I have shot several different firearms with my lights mounted at varies runtimes and have had no problems. Numerous drops have also been encountered with no damage to the lamp.
The gold plating has been maligned as a featureless feature (some have said it wears off quickly) but I have found that none of my models have shown wear in this area and the contacts seem to stay cleaner than the usual system seen on other lights.
They also have their own brand of batteries but I have mixed feelings about them. I ordered 48 batteries and blew through about half of them in about 4 months, then I bought a ZTS tester and decided to test the cells. I found that every unused, new cell registered 0% and gave significantly reduced brightness and runtime in Xenon lights and significantly shorter runtime in regulated LED lights. I hadn't noticed because I was using an L3 at the time and assumed my use was heavier than normal but I was a little miffed when I realized most of the batteries I bought were dead. I chose not to notify Pentagonlight mainly because I used a fair amount of the batteries before noticed and I am spectacularly lazy during the fall and don't have time to deal with my hobbies. I will say that this was about a year and half about when I bought the cells and have not tried any of their cells since. If you purchase them I recommend testing them before use.
The integral mount lights seem to have a strong following with the AR15 crowd and have been spotted mounted on rifles used by both police and military personnel. I don't have any of the mounted lights because they cost significantly more than their handheld lights and I already own duct tape; but from what I have read and heard they perform well.
I don't know anything about their filters, holsters, tape switches or laser lights. They do have a snazzy glow in the dark t-shirt though. Also, their catalog is very nice but is not free (they may send you one if you ask nicely though :thumbsup
Here are some shots of the X3 and the L3
